ElectroJeep - All-Electric Jeep Cherokee

Rudman Mk3 Digital Battery Regulators

2010-09-25T21:18:00.000-07:00

The ElectroJeep has been a little idle as a project as I've been engaged in other things - such as upgrading the Volt914 to 216V. However, with that out of the way, I've returned to it. If you remember, the BMS I installed originally was a PakTrakr (scroll to the bottom of this page) with Zener diode regulators. This sort of worked - but I was very nervous about putting full amps into the batteries, and the PakTrakr has the unfortunate side effect of draining the first in its string of 6 or so batteries. Not a good combo - several of the batteries were getting seriously out-of-balance, and the Jeep was sitting at 325V after a "full" charge.

So, I finally got around to replacing that system with a much better one, based on Rudman Mk3 regulators from Manzanita Micro:

These are designed to connect to each battery. In addition, they are connected to each other and to the PFC-20 (soon, PFC-30) charger to tell it when the battery is getting full. I installed the older analog model on the Volt914 - the digital model lets you adjust the cutoff voltage dynamically, so I can actually charge the batteries correctly no matter the temperature.

The first thing to do was to make plastic boxes to keep the regulators protected. I started by cutting little corner chunks out of 1/2" polyethylene:

The idea is to weld together a box around these corners, which themselves become the mounting points for the transparent covers. I had previously obtained a plastic welding kit, which included the welder as well as various plastic welding rods (including polyethylene):

The boxes are of various dimensions, to hold different numbers of regulators. After calculating dimensions, I cut out the basic shapes from 1/4" polyethylene, and then cut bending tracks where the sides will fold up:

Four of the corner pieces go on each box. Here is one box, from the inside (before folding). Note that the corner chunks of the envelope have been removed here:

Here is the same box from the outside. I used 3/4" self-tapping screws (although I also drilled pilot holes). These screws are mostly to hold it together long enough to weld, although I never bother removing them:

The next step is to fold up all four sides and then screw them to the corner pieces:

The corners are then welded (and a bit of the long fold is welded as well, to add strength). Holes are drilled for cable egress, and smaller holes are drilled for the nylon screws which hold the regulators securely in the boxes:

And here are all seven completed boxes. One of them has some of the wiring attached:

The next step is to attach the connectors which will allow me to easily connect and disconnect the boxes for servicing. I use WeatherPak connectors - you can see them here grouped in the order in which they will be used in each box. In addition, you can see the 12-gauge wire I use to hook the batteries to the regulator. 100 feet of red and 100 feet of black were just plenty:

Here is all the wiring complete. I call this the "14-armed monster". If you look closely, you can see that the internal phone-wire style interconnects are also attached:

Next step is to construct connectors to attach to the batteries. A note on safety: before connecting the ring terminals to the battery bolts, it is safest to insert the pins into the shells - this prevents them from rattling around and perhaps making a circuit with another battery post:

Another note on safety - all the tools used near the batteries have been wrapped in electrical tape within an inch of their life. Note that there are still a few exposed metal places - particularly on the torque wrench - to prevent from interfering from the operation of the tool. Nothing is 100% safe, but every millimeter that is covered in tape is a millimeter that will not close a high-amperage circuit - I've experienced that once, I never want to try it again:

So, with the process established, it is just step and repeat. Here is the lower rear battery box all wired up. You can see that each battery has both a red wire and a black wire. In the connector, the red and black wires alternate - this makes it easier to verify that they are correctly paired, and less likely to make a catastrophic mistake:

Here is the upper rear battery box, complete. Note that, before connecting the batteries to the boxes, I use an ohm-meter to verify that the connections go where I think they go - better safe than sorry:

Here are the under-seat batteries and their regulators:

And here are the front batteries and regulators:

The next step was to interconnect the regulator boxes with the 6-wire phone cord, and then verify their correct hookup by flipping DIP switch 6 on the charger and turning it on (with the amp knob turned to zero). Here are the rear regulators - the yellow lights indicate that they are all talking on the regulator bus:

Here are the under-seat regulators glowing:

And here are the 8 front regulators in the big box glowing:

And finally the lonely little battery at the end of the string with its regulator glowing:

With the regbus wiring verified, and the boxes closed up again and everything connected to enable the full 312V circuit, it is time to charge! For a test point, I disconnected the DC-DC converter and used its HV input lines as a convenient place to plug in a multimeter:

In the rear, I used a clamp-on DC ammeter to verify the current going in to the pack (the new PFC-30 has a built-in ammeter so this step will not be needed):

You'll note that the ammeter says "10.02" - that's not a full load. As I mentioned before, the batteries were significantly out-of-balance. So, a few of them got to full charge first. The most problematic were two batteries in the front compartment. Here you can see me blowing a fan on them to cool them down - this helps the regulator dissipate excess current more effectively. The overheating regulators are the ones with the glowing purple lights:

There were a few regulators in the back that also got hot, so I took the covers off and applied significant airflow to them. Note the hot air gun at the lower right - it was turned to blow cool air, not hot air:

A combination of lots of cooling air along with turning the charger down to output 3 or 4 amps finally allowed things to settle down and charge. Here you can see the green lights of several regulators in the back glowing - this means the regulators are bypassing current but not overheating:

At this point, the pack is nearing full. We've reach 371 volts or so, and the constant current phase is over. Now the charger switches over to constant voltage, ramping down the amps as it counts down on a timer. I set the timer close to the max - the batteries seem to require it. You do not want to cut off this phase prematurely, or the batteries will not be charged. Here is the voltmeter monitoring the constant voltage phase:

Finally, at the end, the timer completed and everything was done. The green, yellow, and blue lights on the charger are normal, and indicate that everything finished OK:

And here is the pack the next morning. 333.5 volts is by far the highest the pack has achieved in a year, and a significant improvement over the 325 volts or so it was getting before. This is an average of about 12.8 volts per cell, which is where it needs to be:

This process will need to be repeated a few times before the batteries stay more balanced. To facilitate that, I will be installing fans on all the regulator boxes (so I don't have to grab all the household fans every time I want to charge). In addition, I will soon be upgrading from the PFC-20 to the PFC-30 charger. This will allow me to charge at up to 30A input at 240VDC - which translates to allowing me to charge at 16A at 370VDC - 16A is the recommended C/5 charge level of the AGM-1280T.

This process took several hours per night over the course of a week. And I'm exhausted. But it is nice to be making forward progress again.

Full Sketchup model, updated

2009-07-01T20:36:00.000-07:00

I have updated the full Sketchup model of the ElectroJeep and uploaded it to the Google 3D Warehouse. You can play with this preview image if you don't want to download Sketchup:

Click the "3D" button in the middle of the picture. You can then click the model and move the mouse left and right to rotate the view.

Add-a-Leaf

2009-06-27T20:37:00.001-07:00

Today I finally got around to fixing the sagging rear end. Although I had added a lift kit, the weight of 950 pounds of batteries in the rear end was just a bit too much for them. After thinking about it for a while, I decided to get an additional Old Man Emu leaf spring to insert into the pack.

The first step, of course, is the same as the original lift - remove the old springs. Jack up the Jeep and add heavy-duty jack stands. Also, put jack stands under the rear axle. Unbolt the shock from one side, let the axle droop (being careful to avoid breaking flexible lines), and then unbolt and remove the leaf springs, with a liberal application of elbow grease.

Here are the springs next to the add-a-leaf. The new leaf is nearly as long as the whole pack, designed to support the main spring. The "pointy" end goes on the rear, where the shackle attachment is. The "blunter" end goes toward the front:

To prevent sudden explosive unspringing of the pack, I clamped it and then unbolted the center bolt. I then gradually unscrewed the clamps, allowing the leafs to separate:

And here is the pack disassembled. The add-a-leaf is shown placed between the main leaf on the left and the rest of the pack on the right:

Assembly, as they say, is the reverse of disassembly. Before assembly, though, I applied liberal amounts of grease to the new leaf. To keep the leafs aligned I inserted a screwdriver in the bolt hole, and then clamped down. When it was clamped down tight, I removed the screwdriver and replaced the bolt. I then alternated clamping down even tighter, and tightening the bolt:

And then, I replaced the leafs on the Jeep. This went a lot easier than last time - not sure if I'm better at it, or if the year of sitting on them has made the leaf pack "remember" the approximate distance between the front and rear eye:

And here is ElectroJeep, all happy and level with its new add-a-leaf. It rides very nicely, now, too!

Edit (Jul 31 2009)

By request, here is what the Electrojeep looked like before the add-a-leaf (this photo is from a post in January). It actually got a bit worse after this - I added 1.5" spacers to the front springs to get more clearance above the front differential. Unfortunately, I don't have any pictures of the whole Jeep at that point.

Gauges, and legal to drive!

2009-06-26T20:14:00.000-07:00

Over the past week, I've squeezed some 12V wiring work into odd moments here in there. This all culminated in getting the dashboard gauges (mostly) in place. It all started with the main cluster. Before putting it into place, I needed to splice connections into this connector, which fits into the gauge cluster to make the lights work:

The connections on this connector are as follows:


              +----+----+
         Gnd -+  1 | 18 +- Illum
              +----+----+
   Left Turn -+  2 | 17 +- Hi Beams
              +----+----+
         n/c -+  3 | 16 +- Right Turn
              +----+----+
       Gas A -+  4 | 15 +- Keyed +12
              +----+----+
         Oil -+  5 | 14 +- Gnd
              +----+----+
       Gas C -+  6 | 13 +- Illum
              +----+----+
       Illum -+  7 | 12 +- Batt
              +----+----+
   Gas Tank? -+  8 | 11 +- Water
              +----+----+
    Gas Tank -+  9 | 10 +- Illum
              +----+----+

I spliced in connections for the new gauge lights (the red and black cables - into wires on pin 1 and 18), and a connection for the gas tank light, which will light up when the Jeep is plugged into the wall and the key is turned on (i.e. - don't drive away you idiot!):

I then hooked in a 3-way wye into each of the illumination splices (there are three new gauges):

I also pulled all the wiring through the bulkhead into the gauge area. It made quite a spaghetti mess. Note the circular "thingy" toward the left side (inside the oval hole in the white surface). That is the original mechanical speedometer cable. It was the source of much, umm, "amusement" down below...

Underneath, I needed a good source of keyed +12V. Turns out this orange wire is keyed, and normally drives power door locks and power windows. I have neither, so this wire is actually very under-used. So I spliced into it for the brake relay and 312V ammeter:

Back in the engine compartment, I made looms out of the control wires, and put flexi-guard around them:

I removed the original bulkhead grommet, and enlarged the hole so all the wires could pass through it. Removing the grommet was highly entertaining, as it apparently was molded into place on the original wiring harness... but with enough cutting & hacking & cursing, I got it out and modified:

And here it is back in place, with a generous dollop of silicone sealer around everything. I also added sealer to the original hole where the throttle cable had gone (the square hole toward the lower right):

Back in the cabin, I neatened the spaghetti explosion into a loom and added flexiguard here too. This is especially important to protect those 312V wires that control the volt meter - although they are fused, I hate to risk more damage than necessary:

And here is the gauge cluster snapped into place. This was actually a *lot* more work than it sounds. It was a real pain to get the gauge cluster electrical connectors plugged in - despite the loom organization, the longer 16 AWG wires kept getting in the way. And then, the speedo cable was a *real* royal pain to get back into place. I finally found that unscrewing a mounting screw down under the engine gave me enough slack that I could pull the cable forward and get it to snap into place. It took me 15 seconds to type that. It took me 2 hours to figure that out and do it:

I then put the cluster face on, along with the 12V ammeter and 12V voltmeter. Here is everything plugged in and lit up. Note the ammeter showing about 40A - that's power steering plus power brake pump plus headlights plus turn signal plus brake light. Not too shabby. The DC-DC converter puts out 55A. I should almost never tap into the aux battery:

With all that in place, the ElectroJeep is now fairly road-worthy. So I took it on the road. I took it down to our local Jeep dealer and had a VIN verification done. I then took the paperwork down to our local county courthouse DMV, and got the Jeep retitled as Electric! Note the circled "FUEL E" designation. Unfortunately, they will mail me the actual title, so I don't have an image here, so the registration will have to do:

And here is the license plate with its new registration tags - all ready to drive legally on the roads!

One more note - I drove it about 11.6 miles round-trip to get the VIN verification done. It took roughly 4.6 KWh to recharge the batteries after I got home. This translates to 400 watt hours per mile from the wall - which compares pretty favorably with 379 watt-hours per mile for the volt914. Of course, I was driving 25-30 MPH the whole time, but I do not have the regen braking hooked up yet. So 400 is probably the right number. This translates to a range of roughly 50 miles at 80% DOD. We shall see...

Misc Wiring

2009-06-21T21:51:00.000-07:00

I also spent some time doing more wiring cleanup on the 12V system. I removed the molding from the driver's side doorways and routed the PakTrakr cable from front to back under it:

I also found the brake light wire (the blue wire with the black stripe):

I crimped a connector on so the regen brakes will light the brake lights when I enable them:

I did a little more under-hood wiring cleanup, but no pix yet. Working toward getting the dashboard restored...

Zener Diode Battery Regulators

2009-06-21T21:32:00.000-07:00

I got tired of worrying about the balance of my batteries. I had been charging them individually - I'd tried a bulk charge once but it overcharged several batteries. I think I even caught a whiff of hydrogen sulfide - if so, it means one or more of the batteries outgassed. Very bad for sealed batteries.

So, while I wait for a more advanced BMS, I decided to build some Zener Diode battery regulators. I found a very nice writeup here (PDF instructions here) and followed it fairly closely.

First, you start with the components - from the left, they are:

10 Ohm 1W resistors
5/16" ring terminals
6.8V 5W zener diodes
1/2A miniature light bulbs

I soldered the resistors to the light bulbs:

I then soldered half of the zener diodes to ring terminals, making the positive terminal (the stripe goes toward the terminal for the positive terminal):

I then soldered the light bulb / resistor assembly to the diode / terminal assembly. Three of them have a wire in between due to physical layout issues with the rear battery rack:

I soldered the other half of the zener diodes to the negative terminals - the silver band goes *away* from the negative terminal:

And then I soldered a 16 AWG wire in between the positive and negative terminals, heat-shrink wrapping the ends for added strength:

And here are all 26 zener diode battery regulators. 9 of them got an epoxy / potting treatment (they are the ones that live in the front compartment, they need to be a little more water tight than the rest):

Here you see the regulators on the front rack:

And here they are on the rear rack. Note the three regulators on the batteries closest to you - these are the ones which I put extended length wires on so you could actually see them (otherwise, they would be hidden by the lip of the rear compartment):

With all the regulators in place, time to test them. I connected the CamLok pack disconnects, hooked up the charger, plugged it in, turned it on, and... light! I had previously charged the lower rear rack batteries, so the lights came on immediately:

The idea behind the light is that when the lights are on you should reduce the charging current. This was with a 5A charge current - pretty low - but until I get a more automatic system, what this means is that I will have to go watch the lights and turn the amps down on the charger manually when they start to come on.

The one thing I note is that having the regulators makes monitoring the individual battery charges with the PakTrakr kind of wacky. Sometimes the batteries would register very low (i.e. 8.6 volts). This effect goes away when the batteries are not charging - I suspect the extra shunt action between the positive and negative battery terminals confuses the poor PakTrakr.

All in all, a very successful week of work. I estimate that each regulator took about 20 minutes (there were 9 solder joints on each one), so this is about 10 or so hours of work all told.

ElectroJeep - A Summary

2009-06-18T18:38:00.000-07:00

This is a summary of the ElectroJeep project. Although the project is not 100% complete, it is close enough to document. I will update this posting as the last few items get done.

The project started in January of 2008, with the donor vehicle - a 1988 Jeep Cherokee XJ:

I decided to go with Azure Dynamics' AC55/DMOC445 motor/controller combination, along with various interfaces which they provide:

The first step in any conversion is removing the Internal Combustion Engine. This typically requires an engine hoist and lots of elbow grease (and lots of real grease, too):

I also decided to go with lead-acid batteries. The weight this adds requires an upgrade to the suspension, so I purchased a heavy-duty lift kit (Old Man Emu):

Here is the front installed, along with a 1.5" lift block to provide enough clearance between the motor and the front differential:

Here is the rear installed. Yet to be done - I need to install an Add-A-Leaf kit to compensate for sagging in the rear:

Here is the Jeep with the lift installed and with essentially no weight inside - it makes it look like it will ride very high. This is an illusion. Once I add 500 pounds of motor, transmission, and battery racks, along with 1500 pounds of batteries, it will ride very close to where it started.

The motor is mated to the original transmission via a custom-built profile plate and hub from Electro Automotive. Here, my daughter KatC torques the bolts to spec:

Here is the motor mated to the transmission. Note that in the final design, the motor is actually rotated 180 degrees upside-down from what is shown here:

The motor is mounted via a cradle system which attaches to the original motor mounting points:

Thus. Here you can see that the motor is in fact "upside-down" to provide maximum clearance above the differential along with adequate spacing below the front battery rack:

The batteries themselves are sealed 12V Group 24 AGM batteries - the Concorde Chairman AGM 1280T. They weigh 55 pounds each, and are spec'd to 80 amp-hours of juice:

I designed racks to hold the batteries and welded them from 3/16" angle stock. Here is the front rack, which holds 8 batteries:

This is the rear rack, which also holds 8 batteries:

This layout is required because this rack is sunk beneath the floor of the rear cargo space, and I need to avoid cutting structural members:

This is a third rack, the Upper Rear Battery Rack, which holds 7 batteries:

Under the rear seat are two batteries in individual racks:

Here you can see one of the racks welded into place:

The last battery is mounted in the front compartment in the same orientation as the original 12V battery, but on the driver's side. There is also a 27th 12V battery in the original battery location which provides power for all the 12V systems in the Jeep.

The batteries are interconnected with 4/0 gauge welding cable. Where it is exposed to possible damage, it is armored by plastic conduit:

The batteries in a rack are interconnected with copper straps. There are three 1/16" by 1" straps connecting each battery, which provides close to the same (low) resistance as 4/0 welding cable. The straps are bent to provide some degree of flexure to avoid levering the bolts out of the battery threads:

A variety of electronic components needed to be added. Here are some high-voltage fuses and a high-voltage relay:

Also, various 12V systems needed to be changed. Here are a circuit breaker and relay for the new electric power steering pump (see below):

This box contains several relays which interlock various systems. These relays do things like inform the controller that the system is plugged into the wall (so that you can't drive off when plugged in), they control the 300+V heater current, and they also control the DC-DC converter (see below):

In the rear, the charger is mounted. This charger can do the bulk charge of the full 312V string of batteries (the charge voltage is 372 volts!):

The charger connects to an inlet placed in the original gas tank filler location:

Various components in the front (power steering pump, controller, DC-DC converter) also required custom welding of racks:

Here is the electric power steering pump mounted and hooked up:

And here is the power brake vacuum pump and reservoir (note that the rat's nest of wiring has been cleaned up since this photo was taken!):

Here is the DC-DC converter in place. You can also see the 12V accessory battery. The 26th traction battery is mounted in the same orientation on the driver's side:

Also, the heating system was changed to electric. Two 400V 1000W ceramic heating elements were ganged together and placed in a custom box inside the heater box:

The throttle now operates a potentiometer in this "pot-box":

And the gauges have been upgraded to show various information necessary to run an electric vehicle. Shown here are the high-voltage volt meter (in the former gas gauge), along with new 12V amp and volt meters. Not shown are the 200A traction battery amp meter nor the PakTrakr battery monitoring system:

And that's where it stands. The vehicle is operational, mostly, but not yet street legal nor registered with the State. As I said, I will update this posting when the final bits-and-pieces are complete, so watch this space...

DC-DC Converter Installed and Wiring Cleanup

2009-06-13T21:18:00.000-07:00

I installed the DC-DC converter - the Azure Dynamics DCDC750 BC12 battery charging unit. First, I had to build a few cables. These are the high-voltage cables. The red Anderson connector actually goes to the heater, not to the converter. The black connector is known as a Yazaki connector - it looks like a better design than the Andersons (for one thing, it looks like it is waterproof - it has silicone seals).

Next, I installed the cabling. The thick 4 AWG cables coming from the battery are new. The unit puts out roughly 60 amps, so you need some pretty hefty cable to avoid a voltage drop and overheating / burning up cables. All of the cables are protected by plastic spiral wrap. In the lower left, you can see that I have installed some twisted pair wiring onto the Hall-effect current sensor - I'll have a full post later about hooking it up.

With the DC-DC in place, I decided it was time to clean up the spaghetti explosion. First, I installed a Power Pole to hook up the 12V battery to the original fusible links which run the electrical system. This replaces a bolt wrapped in electrical tape, which was not a good long-term design.

I also upgraded the wiring to the power steering pump. It pulls up to 60A. I previously had used 10AWG wire - about 8 feet in all. Using the calculator at this site, it showed a likely voltage drop of nearly 1V - which translates to about 60W at max power. Which is a full lightbulb of energy going through a fairly skinny wire. Which could then burn up. Also, this would restrict the power of the pump. I upgraded to 4AWG, which should be plenty adequate (both the positive and negative sides were upgraded).

Finally, I spent quite a lot of time routing cables into looms and making things neat and pretty with zip ties. I still have not permanently mounted these two relay boxes. Going to have to do that soon...

Next up - cleaning up the routing of cabling into the passenger compartment, and, hopefully, starting to hook up the dashboard.

Power Brakes and Stuff

2009-06-07T21:47:00.000-07:00

I squeezed in a couple of miscellaneous things today. I got the vacuum pump for the power brake assist hooked up. It is *loud*. Imagine one of those aquarium pumps you had as a kid. Bzzz. Now imagine ten of them. BZZZZ. I'm looking into mufflers or other options (wrapping it in bubble wrap as shown had very little effect). You can see that the wiring has exploded into spaghetti - soon it will be time to attach everything and put all the wiring together into looms. But for now, it works - I took my wife and oldest daughter for a ride around the block now that steering and braking are not such a pain.

I did get a start on attaching things. I mounted my two high-voltage power poles in the front compartment, directly above the DMOC. The red thing in front of the most positive pole is a Hall-effect current sensor. I decided I did not like the idea of a shunt-style ammeter at 312+ V. This is the sensor for the Shoreline Ammeter:

I also put together an enclosure for the high-voltage fuses protecting the 312V voltmeter and heater. Also in this enclosure are a relay to turn the 312V voltmeter on / off with the keyswitch:

I updated the circuit diagram to include the relay and to show the Hall-effect sensor instead of the shunt:

As always, you can find the PDF here.

Power Steering!

2009-06-06T19:16:00.000-07:00

Today was Power Steering day. If you may recall, last year, I bought an electric power steering pump kit from CanEv. I fiddled with a few things, making a rack to mount it on, but never got it hooked up. I finally got a high pressure hose crimped at my local Parker Store, but other projects got in the way. But finally I got it put in.

Here is the pump, mounted in its home. The thick red wire gets power from a relay and circuit breaker. The thick black wire goes to ground. The black hose with green stripes is the high pressure hose that goes from the pump to the steering box. The thinner blue hose is the low pressure return line from the steering box to the fluid reservoir. The thicker blue hose goes from the reservoir to the pump.

Here is the reservoir, tucked in a corner near the most negative battery in the pack. It is not permanently mounted yet - it's just kind of resting there. This obviously needs to get fixed before driving... Here you can see the three hoses I discussed earlier:

Here are the electronics which turn on the pump. The box on the left is a high power (100A) resettable circuit breaker. The box on the right is a high power relay. The relay is turned on when the key switch is turned on, causing the power steering pump to run. This is all shown on the 12V circuit diagram.

Also this week I have been doing some battery tuneups. The charger I had been using to top off the batteries was clearly inadequate - it never got the voltage up above 14.1V, and the whole pack was dragging at around 12.4V - 12.5V per battery, giving a total pack voltage when "fully charged" of around 318V. The worst thing was that the battery levels were pretty far apart, making bulk charging a risky proposition. So, I got a pair of higher-tech chargers that claim to be able to desulphate batteries - BatteryMINDer:

They actually seem to work well. I have not given any of the batteries the desulphation treatment yet - I'm going to let them all rest until Monday morning and see which ones have sagged the worst. But, as you can see, the fresh charge gets up very close to full now (where "full" is roughly 330V for 26 12-volt batteries):

Next up - power brakes... and cleaning up the rat's nest in the front compartment.

He's baaaack...

2009-06-01T19:55:00.000-07:00

After a hiatus that turned out to be much longer than expected, I'm back at it. This weekend was the first chance to actually do anything - I had to get the garage cleared out after the Voltwagen insanity.

First thing I did was mod the hood. It had not been closing very well with the top on the front rack. So, I took a Dremel cutoff wheel to it and surgically removed part of the support (the grey splotches are primer to keep it from rusting):

Next, I finished the interconnects in the front rack. Six months ago (!) I was in a big hurry to try to get it kind of running so it could move in and out of the garage. So I did not put the heatshrink on the interconnects, nor did I have the PakTrakr fully attached. That has now been corrected:

Finally, I got the charger re-installed. You may remember that it died a few months ago and I sent it in to be repaired. I never did figure out what killed it - my best guess is that a transient voltage spike killed it. Don't know where the transient came from - turns out I had a flaky AC plug that was sparking when plugged / unplugged - maybe that was it? I've replaced it the plug.

A few things of note on this picture. First, I also installed a kilowatt hour meter from EKM Metering (just like on the Volt914) so I can track wall-kWh-per-mile. Second, inside that gray box the meter is sitting on is a 12V power supply. This will provide a few things - a light that shows on the dash when the Jeep is plugged in; and a relay that will tie a signal to ground to tell the controller not to run when it is plugged in. Eventually it may control other fun 12V systems that are needed when it is plugged in. Third, I've provided a ground to vehicle chassis (black wire in foreground) per the Manzanita Micro instructions.

Lastly - next to the gray box - you can see that I have replaced the 5/16 bolts with longer 3/8-16 bolts for the rear hold-down. I was not convinced that the 5/16 bolts were heavy enough. And I could not get a good grip on them with the nuts - they were not quite long enough. So I drilled them out (a lot of fun - hardened hex cap bolts do a number on drill bits) and put stainless steel 3/8-16 bolts in their place, held down by wing nuts.

Short list of things that *must* to be done to make it safe / really driveable:

Hook up power steering
Hook up power brakes
Replace instrumentation (especially speedo)

Short list of things that *should* be done before it is driven regularly:

Install DC-DC converter
Replace some of the dual 2-gauge cable interconnects with triple 2-gauge interconnects (makes it equivalent to 2/0 gauge)
Bolt down some loose electronics boxes in the engine compartment
Put in the add-a-leaf kit for the rear suspension (it is sagging quite nicely...)
Get the clutch working (hook up hydraulics, fill & bleed)

And there is a nearly infinite list of things that can be tweaked after that, including big items such as 4WD.

Brief Hiatus

2009-02-23T08:08:00.001-08:00

I'll be taking a brief hiatus from the Electrojeep over the next 3-4 weeks - I'm building a 5/8 scale model Benz Patent Motorwagen and putting an electric motor in it for a local theater group. You can follow my progress at the voltwagen blog.

See you back here in a month or so!

Declaring Victory and Moving On

2009-02-16T20:56:00.000-08:00

I finally got some time and good weather today to finish up the motor install. Although I had some back-and-forth with helpful blog readers, I decided to stick with my current plan for now. I'll re-examine the motor mounting this summer to see whether anything is being stressed by this design.

Here is the motor from the top. The side bolts have blue thread-lock applied, and are torqued to 80 foot-pounds. In addition, there are washers exactly filling the space between the forks and the cradle to reduce the torsion about the motor mount bushings:

After placing the front rack and batteries, I jumped up and down on the front bumper a couple of times to settle the springs, then took this picture. There are now roughly 4 inches of clearance between the motor and the front differential:

As I said at the beginning, this is not probably the very best motor mount - a torsion bar of some sort between the two forks would be very helpful, as would additional bolts between the forks and the cradle, but it will be adequate for now. I'll consider a rebuild this summer.

Pumpkin Interference, V

2009-02-08T21:04:00.001-08:00

Man, this motor mounting project has turned into a pain... This week, I finished the motor mount I had designed last week. I cut it, welded it, bolted it, painted it, and installed it on the motor. When I went to install the motor, the trouble started... but let's step back in time first. Here are the original parts, all primed pretty:

The bolts are torqued down to 25 foot-pounds per typical specs on Grade 8 hardened steel bolts. The primer is just rattle-can metal primer. The welds are there to keep everything aligned more than for structural purposes - the bolts themselves are plenty strong to hold everything together. The two longer parts I call the "cradle" since it cradles the motor feet. The two shorter parts are called the "forks" for obvious reasons (they go around the motor mounting bushing).

I finished painting the parts (rattle-can black) and mounted the cradle on the motor. The 3/8" bolts holding the cradle on were torqued to 45 foot-pounds, along with some blue threadlocker. Those guys won't come off unless I want them to. The forks are temporarily mounted for photogenic purposes. The handy thing about the cradle is that it provides a good place to loop chain or cable around for lifting with a hoist:

And here is where the trouble began. I'm not sure how, but I measured the distance between the two motor mount bushings incorrectly. I measured it at 19" - but it is really closer to 18.5". This means it is impossible to mount both forks at the same time. In this picture, you can see that I have mounted the passenger's side fork, but that the whole motor is pushed over toward the driver's side about one quarter to one half an inch:

Because of this skew, I could not install the driver's side fork. So, I put a temporary bolt on the driver's side just to support the motor while I went back to the drawing board (this is obviously only a temporary measure):

The good news is that there is sufficient clearance between the highest point on the motor mounting system and the bottom of the front battery rack (so at least I measured *something* correctly):

After much thinking, I came up with a new design. The issues were:

The current design is too wide
But I can not make the fork tines shorter while still using box tube because the main 1/2" bolt head will interfere with the motor mount bushing retainer
Additionally, the box tubing on the fork "tines" was too thick to easily get a nut onto the bolt that goes through the bushing
And, I'm not happy using threaded rod - I'd rather use a grade 8 hardened steel bolt thru the motor mount bushings, and those typically only come in 6" or less lengths (unless you special-order them).

I finally realized that I could do three main modifications to the fork design:

Replace the long box tubing with an angle iron
Shorten the tines by 3/4"
Cut the tines in half at the motor bushing bolt end to make more clearance for bolt heads etc.

So, I did it. Here is a rendering of what the completed motor mount will look like with the modified forks:

Here is an exploded view of both the driver's side cradle as well as the new driver's side fork:

And, I built and painted the new forks. Installation will have to happen some time this week or next weekend. I'm out of daylight...

You may find a PDF of the blueprints for the driver's side motor mount (both the cradle and the fork) here. Note that the passenger's side is a mirror image of the driver's side.

All this for a stupid front differential... if only I could have found a two-wheel-driver front axle and transmission...

Pumpkin Interference, IV

2009-01-31T20:19:00.001-08:00

It's full steam ahead on the "rotate the motor 180 degrees" project to overcome the pumpkin interference. I removed the motor and installed the new mounting points and bushings:

It was not strictly necessary, but the old ones were in questionable shape, and these are heavier-duty (designed to support the 4.0 liter engine). I also rotated the profile plate 180 degrees - note that the motor "feet" are now on top:

And I cleaned up and cut all the metal pieces for the motor mounts:

I spent some time drilling holes, but there are quite a few more holes to drill and welding to do. Cooler weather is rolling in; hard to tell how much I'll get done tomorrow...

Pumpkin Interference, III

2009-01-30T22:26:00.001-08:00

I spent most of my spare hours this week wracking my brain for a solution for the motor mounting problem. I finally bit the bullet and drew a very accurate SketchUp model of the AC55 motor, plus a drawing of the new motor mounts & bushings. I also carefully measured the distances between the motor mounts, as well as the angle of the motor (5 degrees). Using all this information, I figured out a motor mounting scheme that, although a little baroque, I think will work very well:

Here is just the left side, from behind. The new mount has mirror-image left and right sides. Each side is composed of two parts which swivel about a large 1/2" bolt. Below, you can see the two parts - one of them is bolted to the motor mounting point, and the other gets bolted to the motor. This pivot allows some adjustment to be made to the motor angle (I'll probably also enlarge the hole that the pivot bolt goes through to allow for some adjustment). The two halves will be welded together, but there are 1/2" bolts on the part that attaches to the motor to give it more tensile strength:

Here are a few exploded views of all the parts. Once I get this built accurately, I'll take final measurements and update with a PDF drawing of the assembly:

Tomorrow promises to be warm-ish (55 degrees) and sunny - perfect welding weather... hopefully I can get this completed in one day.

Pumpkin Interference, II

2009-01-27T18:44:00.001-08:00

After some thought, I've decided on a combination of approaches to solve the motor / differential interference. First, I bought some aluminum 1.5" lift spaces and installed them this weekend (side note: I'm tired of wrestling these springs. This is the *last* time I remove / reinstall them...):

This shows the clearance gained by doing this:

That's without batteries installed, of course - with 500 pounds of lead in front, and with a new adjustable trackbar installed, I expect that clearance to shrink to about 1.5 inches (which, no surprise, is the height of the new spacer).

Next, I'll gain another inch by either rotating the motor 180 degrees or by moving the motor mounting points back (stay tuned...)

It's been really *cold* this week, so that is likely all until this weekend.

Pumpkin Interference

2009-01-17T20:01:00.000-08:00

No, not the gourd - the differential case is sometimes known as the "pumpkin". As I was preparing to put the ElectroJeep back in the garage for the miscellaneous final things that need to be done, I took a look at the front differential - I expected the springs / shocks would have settled some after going over the curbs, etc. And I was right. The motor mount was resting on the front differential. This is very bad - going over a bump with any significant force would cause serious damage. In fact, even the 100 gentle feet I drove caused damage to the mount - see the lower left corner - bent and scarred (this picture was taken with the Jeep jacked up, so the front axle is dangling):

So, the whole thing needs to move up. I have about an inch of clearance on top:

I also need to move the crossmember toward the rear of the Jeep. This causes, umm, interesting challenges if I am to use the original motor mounting points. Here is one design, showing a heavy 1" box tubing framework that pushes the hanging point toward the face of the motor (it would all ride on a 1/2" threaded rod, shown, that runs the whole length of the assembly):

I would also have to remove most of the aluminum foot on the driver's side of the motor (highlighted in blue here). This would give me nearly two inches of clearance - and I could put a rubber "bump stop" or something down there in case of an extreme bump.

The other option, not shown, would be to rotate the motor 180 degrees so the "foot" is on top, and the motor is hanging from a support stretched across / between the two motor mounting points. But the size of the foot means that there would not be as much clearance between the differential and the motor. And I think I need all the clearance I can get...

More Motor Notes

2009-01-09T21:23:00.000-08:00

I stumbled across some data on the Jeep's original engine and its performance. The original gas engine was an "AMC 250 I4" - a 2.5L 4-cylinder engine. This curve shows its torque versus the various electric motors I have data on:

Here is its horsepower - immense at high RPM. However, nobody runs the engine at race-car speeds of 5000+ RPM. When we drove it around before, we typically kept it under around 3000 RPM because nobody liked riding in the Jeep with the engine / tranny screaming like a banshee:

Using the data on the gearing ratios of the AX-5 transmission and Dana 35 rear axle, here are the various shifting ranges. The solid lines are the AC55; the dashed lines are the original AMC 250 I4. I assumed that both gas and electric would not be run at more than about 3000 RPM to make this chart.

Again, this highlights why you want a transmission. Although you *could* just run around in 4th gear all the time, you'd be really slow off the line as you started. And running electric motors at low RPM is fairly inefficient.

It will be interesting to see if that comparatively low performance above 60 MPH will limit the vehicle usability in any way. I suspect not - it is an in-town vehicle. Even at 75 MPH it's only missing about 15% performance relative to the gas motor.

For future reference - I believe the gearing ratios of my Jeep are:

First gear: 3.93
Second gear: 2.33
Third gear: 1.45
Fourth gear: 1.00
Fifth gear: 0.85

The Dana 35 final axle ratio is 4.10, and I'm assuming I'm running 31-inch tires.

It's alive! Really alive!

2009-01-08T18:23:00.000-08:00

YouTube link.

After some email back-and-forth with Azure Dynamics, they figured out that I had incorrectly labeled my 3-phase motor cables. I had swapped "A" and "B". To keep the lengths properly aligned ("C" must be 1.5 inches longer than "B", and "B" must be 1.5 inches longer than "A") and to avoid further shortening my motor cable, I made up three patch cables of the proper lengths. The labels on these patch cables are "AM" for "A, motor side", "AC" for "A, controller side", "BM" for "B, motor side", and so forth:

I unbolted the motor cable, and bolted the extensions on with stainless steel hardware:

I heat-shrink wrapped all three:

I still had the shielding braid from the really long cable, so I cut a piece to an appropriate length to splice between the DMOC and the original shield:

I zip-tied the new shield over the old shield, providing a continuous ground contact, bolted the three cables in, and tightened the fitting:

And it works! I drove the Jeep out and around, and parked it back in our gravel drive:

And here it is, charging next to the Volt914:

Sadly, during all this, the Manzanita Micro charger has developed a fault - it blows the breakers in the house panels when it is turned on. So, I get to send it back for diagnosis and repair. But I can charge the batteries individually for now...

Electric New Year, Jeep Style

2009-01-01T17:21:00.000-08:00

Just like on the volt914, I mounted an "ELECTRIC" label on the back of the Jeep. Happy New Year - and good luck to all those conversion fanatics out there!

Potbox / Throttle

2009-01-01T17:15:00.000-08:00

Today, I mounted the potbox and attached the throttle pedal to it. I started with some 2" by 1/8" aluminum bar stock and made some bends:

And more bends... (sadly, I made this bend backwards):

Here's the final bent-up mount. Because that bend above is the wrong direction, I had to add one more bend to turn the forward extension around 180 degrees. You can see the four holes on that extension where the potbox will be mounted:

Here's the potbox mounted in its new home:

And here's the whole thing in its final location. The springs in the potbox push the lever toward the front of the Jeep. The threaded rod pushes on the throttle pedal. Because of the lever point, this means the footrest on the pedal moves *backwards* and resists foot pressure:

It works fairly well. I may upgrade the 10-24 threaded rod to 1/4-20 - the 10-24 was fine when I was thinking of using the throttle to *pull* the arm back, but *pushing* causes the thin rod to bend a bit, adding some undesirable "springiness" to the assembly.

The Whole Enchilada

2008-12-31T18:58:00.001-08:00

To commemorate the end of the year - and the end of major construction on the ElectroJeep - I made a Google Sketchup model of all the components. It still needs some tweaking - but here is a picture of the work-in-progress. You can download the actual model in the Documents link section to the right (beware - it is large - 23MB).

Happy New Year, and may all your vehicles be electric.

Charger Inlet

2008-12-31T16:56:00.001-08:00

I changed my mind - I wanted to get the charger going so that I could keep the battery pack easily filled up. I started with a plastic cover plate, and drilled a hole in it to match a marine outlet that I had purchased earlier:

The cord for the charger comes out in an outlet box in the former gas tank filler opening:

I threaded the cord through the plate, and attached the wires:

Finally, I completed it by attaching the plate to the box:

Here it is, plugged in and charging:

To avoid damage to the batteries, I am only charging to 330V for the pack (this is roughly 12.7V per battery). I will charge the individual batteries to equalize. This will only be necessary until my battery management system shows up (I already have a PakTrakr installed for monitoring purposes).

Back Home...

2008-12-31T10:16:00.000-08:00

Nothing really to report, but I adjusted the layout of the site and added a bunch of links to the right. Most significant are the document links - these are PDF plans of all the components that I designed for this project.

Today - I'll see if I can get the potbox mounted.

It's (almost) Alive!

2008-12-23T21:16:00.000-08:00

Monday morning - I hooked up the last three wires:

Keyed +12V to relay box
12V ground to relay box
DMOC to 12V ground

I then turned the key, heard the contactor "click" and then - nothing.

I've been here before, of course, so I knew what to do. I hooked up a computer and fired up Azure Dynamic's diagnostic ccShell program. It was registering error code 16 - which I was familiar with from Tim's experience. I checked the grounds, and then set the variable EE2DisableChargedError to 1 which makes the controller ignore the error code 16.

One more time, turning the key on and - noise! Ugly grinding noise, though. The same whether in neutral or in gear, so I'm pretty sure it is coming from the motor itself. I've been here before, too - so I contacted Azure Dynamics tech support. We've had a couple of interactions, with them requesting data dumps & experiments, and me returning data to them.

No results yet - it can move (slowly) forward and backward, but not enough to back it down the driveway. When I get back from vacation, I hope to be able to finish this in the next week or two...

Pushing toward Final Assembly

2008-12-23T21:06:00.001-08:00

I'll be away from the Jeep over the Christmas holiday, so I wanted to get as much done before I left as I could. So, I stayed up until 2:00AM Monday morning working on things. I did some potbox hackery to attach a threaded rod that will (eventually) be attached to the gas pedal. Basically, just a 10-24 machine screw with nylock nuts holding it to the potbox arm, and holding an angle bracket on (the nylock nuts are not tight on the angle bracket - it needs to be able to rotate). The threaded rod goes on the angle bracket, and will be pulled by the accelerator pedal as you depress the pedal:

I attached all the interconnects, flexi-cables, and PakTrakr connections to the lower rear box:

Between the lower rear box and the upper rear box, there are a CamLok connector and a 400A fuse. In keeping with my "no exposed 312V connections" rule, I put the fuse in an electrical conduit box. The red cable is very stiff, so I made the other side a "FlexiCable" connection to give me more wiggling options:

The red end of this cable attaches to the upper rear battery pack. It goes through an opening in the metal, so I added armor to protect it. I cut a chunk of leftover conduit to fit:

And then heat-shrink-wrapped it in place:

And there it is, attached. The interconnects and PakTrakr connections are also finished in the upper rear rack:

I then hooked up temporary interconnects between the upper rear rack and the under-seat racks, and between the batteries. Because I underestimated the amount of 4/0 cable, I had to order some more. It's not here yet, so I grabbed some 2-gauge battery cable and made up some two-wide cables as temporary interconnects (using 2/0 lugs). The circular area of two 2-gauge cables is about the same as 2/0 gauge cable - enough for my purposes for now (it will get replaced with 4/0 cable before I do any significant driving):

And then I finished the hookups in the engine compartment. It was getting late at this point, so I took some shortcuts - I have not heat-shrink-wrapped the interconnects, and I need to adjust the shortest ones so the batteries will line up properly. Also visible in this picture are the relay box, tie-wrapped in its final location in the upper left corner of the picture:

And here is the top on. Unfortunately, that front interconnect is still too tall, and the top does not fit all the way down. I will deal with that after vacation. For now, I'll live with a hood that does not quite close all the way (it latches but does not fully close):

And then it was time for bed.

Feeding the Snake

2008-12-23T20:55:00.000-08:00

In their book, "Convert It", Mike Brown and Shari Prange say the process of feeding heavy cable through conduit is like feeding an uncooperative python. After having done it myself, I think it is more like feeding a live python to a live anaconda... but I managed to get it done.

First, I had to remove the conduit from the Jeep. If the conduit is not fairly straight, the cable will hang up on the twists and turns and not feed through. So, I took it down to my laundry room where it is nice and warm, and proceeded with the feeding.

The long cable has both the 4/0 cable as well as a 10-gauge cable (for the most negative attachment to the charger). So, I taped them together at roughly 12-inch intervals. I then fed a plumber's friend through the conduit, and taped the cables to the wire:

With liberal applications of electrician's slime, and alternating pushes and pulls, I managed to get the cable through the conduit:

The shorter cable (from the rear seat racks to the front rack) went more easily - it is just the cable, and a shorter run, so I was able to push it right through (again, with a liberal application of slime). I finished the ends (one end a CamLok connector, the other end a standard lug):

I also finished the ends of the longer cable - lugs on both ends:

And then I replaced the conduit on the Jeep, but now, with cables!

Brakes, U-Joints, Transmission

2008-12-23T20:45:00.000-08:00

I also finished the brakes and transmission. Because of the under-seat racks, I needed longer emergency brake cables. To change them, you pretty much have to dismantle the whole rear brake assembly. So, I put new shoes and drums on while I was at it. Here is the old assembly:

And here are new shoes, springs, etc. (on the other side):

And here is the new drum. The old drum is pretty much rust-colored:

Here are the new emergency brakes hooked up to the handle. I got two Jeep Wrangler YJ '91 or later passenger's side cables, part number 52007522, and hooked them up. I had to extend the threaded rod to meet the cables. This is all as documented on this link at 4x4 Wire. A functional emergency brake is a necessity for an electric vehicle, since there is no "compression" to act as a "motor brake":

I also installed new heavy-duty U-joints on both sides of the drive shaft, and new straps and bolts on the differential end:

Not shown, but I filled the transfer case and transmission with fluid. I used a suction device to fill the transfer case, and I filled the tranny from the shifter rod opening until it started to drip from the fill hole.

Shortening the Motor Cable

2008-12-23T20:40:00.001-08:00

The main motor cable was far too long - I would have had to wrap it around the engine compartment 2 or 3 times - so I asked Azure Dynamics about it, and they had instructions on shortening it. It is pretty straightforward. First, you remove the shrink wrap and/or electrical tape from the end of the cable:

Then you strip off the heat shrink as far down as you need it (make the cable longer than you expect - much easier to cut it shorter later if you need, hard to stretch it longer...):

Trim the grounding braid, again, a little longer than you expect:

And then, label the individual wires below the point where you will cut them. Cut the "C" cable 1.5 inches longer than the "B" cable, which is 1.5 inches longer than the "A" cable. Crimp on 2-gauge lugs, and you're nearly done:

The last step, not shown, is to heat shrink over any extra grounding braid, and tape up the 3-phase cables as you found them originally. With this mod, I have a little slack from the motor to the controller, but not so much that it will be dragging on the ground. I removed about 4 feet of cable.

More 12V hackery

2008-12-23T20:27:00.000-08:00

I've actually been so busy on the Jeep the last couple of weeks, I've not had time for blogging. The next few posts will make up for that...

First, I did some work on the 12V relay box. I made the cables that will attach the box to the DMOC controller and to the dash instrumentation. The DMOC cables use GM WeatherPack connectors - which are very handy things, well-sealed and robust.

You start by collecting your pin, seal, and crimper:

Push the wire through the seal, and crimp the pin on to the wire and on to the seal:

Push the seals through the connector, close the end, and you're all done. About 1 minute per pin once you get the feel of it. Here is the relay box with its cables attached (the ones at the lower left connect to the DMOC, the ones at the upper right connect to the dash instrumentation).

After looking closely at the wiring diagram, and after deciding to get a 120/240VAC to 12VDC power supply to integrate into the system, I realized two things. First, the glass fuses were pretty much all for the AC power supply and relay. Second, with those fuses gone, there was plenty of room in that box for the heater contactor. So, here is, I believe, the final 12V diagram:

And here is the assembled box, integrated in (the dash wiring is not complete, nor is the heater wiring, but the box is hooked up to the keyed 12V (yellow wire on the left), ground (black wire), and the DMOC:

The current wiring diagram PDF is, as always, here.

Odds and Ends

2008-12-16T00:05:00.000-08:00

I also test-fit my copper interconnects, and found I had made some of them 1/8" too tall (and a few of them are marginal in their length). Fortunately, changing the 90-degree bends to 75-degree or so bends dropped the height just enough and increased the length just enough:

Also, this Saturday I got started on getting the transmission put back together for real - I hooked up the wires, reattached the tail cone (including a gasket), and read up on replacing the U-joints. That's as far as I got, though, since winter has arrived with sub-zero temperatures, so I'm working on "things that can be accomplished inside" for the moment.

Controller Power Input Cables

2008-12-15T23:53:00.000-08:00

Remember the Cam-Lok cable connectors? I finally installed a couple of them. I built the cables that are the final terminal into the DMOC controller. As you may recall, 4/0 cable is too thick to pass through the strain relief fittings on the controller. After debating several options, I decided to use 3/0 cable for this section. I got a few feet of red and a few feet of black and went to town.

First, I cut the end of the Cam-Lok connector so it snugly fit over the 3/0 cable:

Next, I slimed the cable with electrician's cable-pulling slime:

Then I pulled the cable through the housing:

I stripped the end the required length (somewhat longer than a crimped lug requires):

Then I wrapped the copper shim around the end, and tightly wrapped the copper strain relief wire about 1/2" below the stripped end, twisting it and laying it against the shim:

I then installed the brass connector and torqued the screws down to spec:

A touch more slime, and I pulled the shroud over the connector and inserted the retaining screw. All done!

I did the black cable too:

There is a problem, though. 3/0 gauge lugs will *not* pass through the strain relief bushings. And they need to - the tolerance on the DMOC is too tight, the ends of the lugs need to be inside the bushings. Also, 3/0 lugs are too wide - I would need to cut the end of one down (as shown in sharpie on the lug to the left). 2/0 lugs, as shown on the right, are "just right".

So, I clipped a few of the fine wires out so the remaining wires would fit snugly in a 2/0 lug, and crimped it and heat-shrunk it (after making sure the bushings were already on the cable *above* the lug connection - oriented properly). A little application of slime let me slide the bushings over the whole thing:

And here are the completed cables test-fit (but not bolted on yet):

Despite the fact that the overall system uses 4/0 cables and lugs for everything, I think this short 18" stretch of 3/0 cable funneled into a 2/0 lug won't affect performance too severely - it is a short distance, and the resistance delta between 3/0 cable and a 2/0 lug at this distance is nearly too small to measure. In fact, I took my multimeter to identical lengths of 4/0 and 3/0 cable, and I could not find any difference in the measured resistance.

Making FlexiCable

2008-12-15T23:47:00.000-08:00

There are a couple of problematic connections in my battery layout. Particularly, the connection between A4 and A5 in this diagram is tricky. I tried making a traditional cable, but the 4/0 cable I'm using does not flex enough. So, I improvised. Looking up the specs on welding cable, I found that three 2 gauge cables are nearly identical to one 4/0 gauge cable, both in circular area as well as specified ampacity. So, I cut and stripped three lengths of 2-gauge cable (here shown next to 4/0 gauge lugs):

I firmly taped the three together, then fit 4/0 lugs onto them...

...then crimped the snot out of them (after all, who wants snotty cables?):

Here is the crimped flexi-cable:

And here is me flexing it one-handed. I could not come close to flexing the 4/0 gauge cable like this:

I double-heat-shrink-wrapped the ends:

And here it is, snug in its location:

To-Do List

2008-12-07T21:48:00.000-08:00

I also made a list of those last things that need to get done to get the ElectroJeep on the road.

Things that must get done:

Finish 12V wiring
Hook up power steering
Hook up power brakes / heater controls (other vacuum?)
Hook up e-brake
Install potbox (relocate throttle cable?)
Hook up controller wiring harness
Finish transmission:

Put gasket on tail cone
Replace U-joints
Torque to final specs
Hook up wiring
Hook up clutch hydraulics
Fill / bleed clutch hydraulics
Fill with tranny / t-case fluid

Install gauges / controls

Including wiring through to engine compartment

Torque suspension to final specs
Bleed brakes
Install battery interconnects
Cut & install long 4/0 cables
Install PakTrakr
Finish charger wiring
Shorten 3-phase cable
Hook up controller 312V cables

Things that would be nice to have done, but are not required:

Install manual t-case cable
Replace rotors, drums, and pads

Interconnects, Hold-downs, and Conduit, Oh, My!

2008-12-07T21:24:00.001-08:00

Another miscellaneous weekend. First, I tweaked the battery layout - the labels are the PakTrakr sequence that will show up, and gives a handy reference for talking about the batteries. The biggest tweak was battery B5 in the lower rear rack. I rotated it 180 degrees. This lets me use cable to do some of the interconnects. More importantly, it gets rid of the really close interconnect between A5-A4 and A6-A3 that the old design had. There was a potential of 84 volts between those two interconnects, and they were separated by only about an inch. Bad. Now, the biggest potential is 48 volts, found between D3 and D6 and between D2 and E2, in the front compartment. Only half as dangerous... Also, I indicate where the CamLock connectors will go, and have added a key so you can see how I did the bends in the interconnects (you want to add bends to your copper straps so they have a little "give" so they don't pry your battery terminals loose). PDF of the new layout replaced the old one, here.

And then, I got cranking on the interconnects. I tweaked my bending jig - I added a bolt to keep it aligned (and to keep it from falling apart every time I insert a new piece of metal). I also screwed the supporting angle irons into the wood. And, I added a rubber band around the bending irons to gently clamp the copper in place until I am able to place the big clamp. Here is the final bend being made on an interconnect with the adjusted jig:

And here is a large pile of bent interconnects. Only thing left is to drill them and install them. I don't pre-drill them because there are subtle differences in the hole-to-hole spacing.

Next, I finished the hold-downs - as in the lower rear rack, each battery gets a disc of polypropylene above it to firmly hold the battery in place. Most of the discs are bolted through the cover and into the steel hold-down. All bolts are nylon, to avoid any danger of electrical short circuits. Here is the completed upper rear rack:

Here is the front rack, from the bottom. You can see the 8 discs, and the countersunk nylon bolts:

Here's the front rack from the top:

And here are the under-seat batteries:

Finally, I mounted the conduit and the front-back AC cable. The front-back AC cable is needed because the relay that tells the controller "you're plugged in, don't let the idiot behind the wheel drive away" is in the front compartment. This cable is basically heavy-duty 10 gauge outdoor extension cord. I tie-wrapped it to the metal flange underneath the doors:

I also finished mounting the conduit. I used double tie-wraps at several strategic points. The driver's side conduit is a little tricky - there are brake fluid lines and power brake vacuum lines in this area, so I added a loop to the conduit to avoid them all (the tie-wrap that holds the loop in place is attached to a convenient hole in the rear seatbelt reinforcement):

Here is the passenger's side conduit. You can see the double tie-wraps keeping the conduit placed mostly protected behind the frame rail:

And now, bed time...

DANGER - HIGH VOLTAGE

2008-12-01T22:26:00.000-08:00

I made up some signs early this morning that I'll be pasting anywhere there is a cover that can be removed to access 312V (or anywhere there is a cable that can be cut). You are welcome to use them for whatever you want. PDF here.

Front Components

2008-11-30T20:57:00.001-08:00

I got almost all the front components placed very close to where they will go. I reinstalled the front rack, and permanently mounted the vacuum pump and vacuum canister. I test-placed all the other components that will go in the front compartment - the only two items in this picture not in their final location are the Hall effect sensor and the heater contactor:

Here are labels to make it easier to see what is going on:

I'll try to find a box to put the heater contactor in - the guiding principal of the 312V system is to make it very difficult for fingers to come in contact with it.

One problem has become evident - 4/0 welding cable will not fit through the strain relief fittings on the controller. I have a few options:

Go with a short run of thinner cable (3/0 might work) - if short enough, should not cause too much of a voltage drop
Drill bigger holes and use the 1" LiquiTight flexible conduit terminators I've used elsewhere
Just put a rubber grommet on the 1" holes

I'm leaning toward the "drill bigger holes" option right now. Still thinking about it.

Making Short Interconnects

2008-11-29T20:31:00.000-08:00

Today I also started working on the battery interconnects. They will be made from 1/16" by 1" copper bar stock - three pieces for each interconnect. This is so the cross-sectional area (0.1875 square inches) will roughly match the 4/0 welding cable (0.1662 square inches). I could have gone with sold 3/16" by 1" bar stock, but that will be very stiff, and I worry that it will tend to lever the screws out of the batteries as they vibrate.

Anyway, I started with the hardest ones - the short pieces. I cut 24 pieces 3.5" long:

I then bent them to give them a little spring. I started by dividing the bar in quarters:

I then bent both end quarters up by 45 degrees. I used my favorite vice-grip clamps to do this:

Here are the ends bent up:

To create the bend in the middle, I built a little jig. There are two pieces of 3/16" by 1.5" angle stock nailed into a 2/4, and two pieces of 1/8" by 1" angle stock which are the press parts (it's handy that I keep all my waste chunks of metal in a box for future use). I use a bar clamp as the press:

Basically, you insert one of the 1/8" by 1" angle stocks into the valley, then put the copper strap on. Then you put the other 1/8" by 1" angle stock on top, and clamp it down. Screw it down as tight as you can, and you'll end up with a nice 90 degree bend in the middle:

Here are the completed pieces, ready to be drilled and installed:

I should be able to reuse my jig for other 90-degree bends that will be required.

Controller Mounted

2008-11-29T20:26:00.000-08:00

I finally got the controller mounted today. First, I finished attaching the mounting bracket I built a while ago. I cut two smaller brackets to attach to the inside front bumper, and bolted them to the Jeep and to the controller mount:

Next, I measured and cut a piece of 1/8" polypropylene to act as a splash guard under the controller:

Here is the splash guard installed, with the vibration isolation feet attaching it to the mounting bracket:

And here is the controller mounted in its final home. At some point, I'm going to shorten that monster 3-phase cable so I don't have to wrap it 17 times around the engine compartment...

Misc Friday

2008-11-28T20:54:00.001-08:00

Ahh, Black Friday. A day when every red-blooded American's thoughts turn to... electric conversions. Today was a day for some miscellaneous things I've been putting off for a while. First, I actually installed the "extra" battery mount (one of the first parts I welded). There are three 3/8-16 RivNuts inserted, and three 3/16" by 2" bolts through the rack into the RivNuts. The rack is held level above the sheet metal by three 1" spacers (this was required due to the slope of the fender right next to the mounting point). I also used RivNuts as the top hold-down attachment point:

Next, I made a top for the "extra" battery from polypropylene. Because this battery does not have a rack-style enclosure, I decided to get a little fancy and create a lip around the top to prevent curious fingers from accidentally contacting 312 volts. Basically, I just cut half-way through the box along the edges, and then liberally applied heat with a heat gun. And then, with sufficient force, the edges were bent down:

Next, I reinstalled the heater blower. First, though, I identified the main wire that is hot when the blower is active - it's the light blue wire here. I then added a pigtail blue wire on this so that I can control a relay which gates the heater contactor - I only want the 2000W heater running when there is air flowing:

With some help from KatC, I installed the blower assembly. Here is the view from the engine compartment. The two gold braided wires on the right are the main wires for the heater core. The purple and black lines are the vacuum lines which provide vacuum for the flapper box (TBD - how to hook them up....) And the blue wire is attached to the pigtail I just made:

Finally, I spent some time actually going over the factory service manual wiring diagrams in some detail. This allowed me to determine that some more of the factory harness can go (and should go - it just clutters things up). On the passenger's side, this harness goes to the EGR solenoid, the fuel pump relay, and the "B+" relay (basically, a relay controlling a time delay shutdown circuit). None of those are needed for ElectroJeep, so this whole harness gets guillotined:

On the driver's side, this whole harness which emerged from the bulkhead was entirely dedicated to controlling the gas motor. So, it got chopped. Here you can see the final electrical tape wrapping - basically, each wire gets folded back on itself about 3/4", individually wrapped with electrical tape, and then the whole mess gets taped together:

Tomorrow - weather permitting - I'll reinstall the front rack, finish its holddowns, and start working on battery interconnects (!).

Finishing Lower Rear Box Hold-Downs

2008-11-26T19:15:00.001-08:00

The last pre-Turkey-Day thing I did was to finish the cover / hold-down. I cut 8 2.5" discs of polypropylene, and countersunk them to install 1/4-20 nylon screws:

I drilled holes through the top (and through the hold-downs where appropriate) and put the bolts on - note - nylon needs to be finger-tight only (I blew up one bolt making it more than finger tight):

Other things evident in this picture but not previously blogged:

I cut and installed the 1/8" polypropylene for the sides of the upper rear box
I cut, drilled, and painted the hold-downs for the upper rear box (from 3/16" bar stock)
I cut and installed the top for the upper rear box

It's getting *very* close to the final battery hookup. I need to:

Finish installing the heater (so I can mount the front rack permanently)
Permanently install the "extra" battery rack (one of the first parts I welded!)
Finish the upper rear, under-seat, front, and "extra" tops/hold-downs just like this
Cut lots and lots of 1/16" by 1" copper strap for the interconnect (each interconnect will consist of *three* such straps to allow high amperage to flow without excess heat)

Seat Boxes, IV

2008-11-26T19:08:00.000-08:00

I also worked on the under-seat batteries. First, I cut, drilled, and painted a hold-down bar (made of 3/16" bar stock). I also installed threaded rod to hold it down (and a 3/8-16 RivNut in the middle). One note on the threaded rod - it actually goes through the 1/8" angle stock and through the Jeep's sheet metal. Unfortunately, there was not a good flat spot to attach the 3/8" rod - at least, no place where it would stick straight up. So, I just bent it - bending it once should not weaken it (repeated bending would, of course). Here it is:

I cut tops from polypropylene, and drilled holes for the conduit between the two boxes:

Here it is, very nearly complete, with the conduit between the two batteries installed. You can also see the connector for the conduit from the rear rack at the top of the picture, and the connector for the conduit to the engine compartment at the bottom of the picture:

One note - always consult your plans as you cut. You might note that there are *two* cutouts on the box at the bottom of the picture - I had put the batteries in backwards, and cut the openings based on the incorrect orientation of the batteries. As I consulted my plans, I discovered my error, and cut new openings. Not a big deal - but - measure twice, cut once continues to be true...

LiquiTight Conduit

2008-11-26T19:00:00.000-08:00

One of the concerns of very high voltage electricity is protecting the cabling from damage. The cable goes outside the Jeep (underneath) at four places:

From the upper rear rack to the under-seat racks
Between the two under-seat batteries
From the under-seat batteries to the front compartment
From the front compartment to the most-positive battery in the upper rear rack

I am using LiquiTight non-metallic conduit for all these interconnects. First, the upper rear rack to under-seat racks - a short run (I later wrote "DANGER: HI VOLTAGE" with some lightning bolts on the conduit):

Second - the cable to the most-positive battery in the lower rear rack. I drilled a hole and installed the connector:

Here is the conduit test-fitted (you can see the first connection at the upper left, and the yellow rear-to-front AC cord dangling in the foreground):

This is a (poor) shot of the conduit going from the rear seat to the engine compartment:

And here is the conduit coming in to the engine compartment. The long piece looped in the compartment will hold the most-positive cable to the lower rear rack (it will get trimmed to length later). The shorter piece at the bottom of the picture goes to the batteries below the rear seat. It looks a little like Doc Octopus is having his way with the engine compartment...

Still do to on the conduit: tie-wrap it to various strategic points on the chassis (making sure to keep it in-board of the unibody "frame-rails" to further protect it from damage).

Charger Mounted

2008-11-26T18:54:00.000-08:00

I took the week of Thanksgiving off so I could get more done on the Jeep. Glorious weather - into the 60s most days (I love Colorado...). One of the first things I did was to install the charger for real. A few weeks ago, I inserted 1/4-20 RivNuts where required for mounting the charger. This week, I drilled 3/4" holes in the trim to match the RivNuts, and installed it:

I also put in a junction box. The reason for the junction box is that the 240V input needs to be split in two - one part for the charger, the other part for the 240VAC relay in the front compartment which tells the Jeep not to allow someone to drive it off while plugged in. The orange cord will connect to the charging plug. The yellow cord goes to the front compartment. The black cord goes to the charger:

And then I installed the charger (it was much easier to install the junction box *before* the charger). I have put one LiquiTight conduit connection where the charging cord comes in. I did not get a photo, but I have another one where the yellow front compartment AC cord goes through. I have not yet hooked up the AMP connector for the DC output - need to get all the batteries connected, first (hopefully this week...):

Heater, I

2008-11-26T18:45:00.001-08:00

I've been a little lax on the blogging lately - some computer problems on the main family computer slowed me down. All solved now (with a new dual-core processor as well), so, back to blogging.

A couple of weeks ago, I did some major work on the heater. The Jeep's original heater used engine coolant run through a heater core to create the heat. Since the electric motor does not have coolant, a different solution was needed.

As mentioned previously, I obtained two 400V, 1000W ceramic heaters from MorElectric. I also got some high-heat wire, a ceramic terminal block, and ceramic insulation (think fiberglass, but ceramic instead of glass). After extracting the heater core (which was non-trivial - most of the dash needed to be removed) I built a metal box to hold the two heaters, trying to keep it close to the size of the original heater core:

Next, I installed the ceramic insulation. I was careful to wear gloves, eye protection, and a dust mask while doing this - I don't relish the thought of ceramic silicosis...

Nearly done - I installed the ceramic terminal block, hooked up the wires from the heater cores and the new high-temperature 10-gauge wires:

And here it is next to the original heater core:

I test-fit it into the heater box. Not finally installed yet - I'll take some pix and blog it later:

People might notice that I did the heater substantially earlier than I did on the Volt914. The reason is that I need to have the front rack out to access the mounting bolts for the blower box. Much easier before everything is put in place.

12V Wiring I

2008-11-02T20:36:00.000-08:00

I spent some time this week designing and implementing the front 12V system. First, I drew out most of the engine compartment wiring (you can find a PDF here):

I then prepared the relay box. Here it is from the front. You can see the two main relays on the left and right. They are angled this way so the pins will be facing "down"-ish when the box is mounted - I don't trust this box to be 100% water-tight and this will prevent condensation from seeping into the relays. The relay on the left is a 240VAC DPDT relay to handle duties associated with detecting when the charger is plugged in (this is the lower relay in the circuit diagram). The relay on the right is a 12VDC DPDT relay to handle some keyswitch action (mostly: disable the DC-DC converter when the key is switched off):

Here is a view showing the top. There are two rows of 10-place terminal strips. The one in front is row "A" with terminal #1 on the right and #10 on the left. The one in back is row "B". These numbers correspond directly to A1, B2, etc. on the circuit diagram:

There are provisions for 6 keyswitch-controlled and fuse-protected circuits. I am currently using 4. There are also 4 glass fuses for the various signal wires that go out. My current philosophy: fuse early, fuse often. Much easier to replace a fuse than to put out an electrical fire.

Still to do: the charger interlock is drawn correctly on the diagram, but not implemented correctly (the DMOC wants the charger interlock to close a circuit when plugged in; my implementation currently sends a +12V signal, which is not the same thing). Also, this implementation currently disables the DC-DC converter when the Jeep is plugged in. It seems like a good idea to be able to optionally charge up the 12V aux battery when the key is turned on. Again, the wiring diagram above is correct, but the implementation is not quite right yet.

Next up: still have to remove the rest of the dash so I can get at that heater core... you might be able to tell that I am procrastinating on this less-than-fun chore.

Dash, Part II

2008-10-22T21:42:00.000-07:00

I managed to extract the gauge body from the dashboard tonight. Here is the front:

And here is the back - interesting "printed circuit on plastic" technology it has going:

To make room for the depth of the gauges, I had to do some hackery. First, I removed the three clips from the middle (these connected to the fuel gauge). Next, I used a hot knife to remove the surrounds from the former water and oil warning lights:

And here it is - all fitting nicely:

The light at the lower left is the former "fuel low" warning light. I think I'll repurpose it to be the "charge not complete" light. The light at the lower right is the former battery light. It will be repurposed to mean, "ignition key is turned on." There are five empty slots on the light panel to the left. I will use one of them to mean, "the charger is plugged in, so you can't go anywhere" light.

Dash, Part I

2008-10-19T20:18:00.001-07:00

This week I also started work on the dashboard. I need to rip just about the whole thing out to remove the old heater core and install the new ceramic heaters. So, I started disassembling it, removing the dash surround:

and the gauge bezel:

I needed to find a place for these three gauges (from left to right - the 12V voltmeter, the 12V ammeter, and the 200-400V voltmeter):

Also, for the ammeter:

Note that this ammeter does not use a typical shunt. Rather, it uses a Hall-effect sensor, which is much safer at the high 312V potential that the Electrojeep has:

The last thing I needed to find a place for on the dash was the fancy combo switch that Azure provided:

I used a hot knife (basically, a blade on a soldering iron) to enlarge the holes where the water temp warning light and oil pressure warning light had been:

I then used a hole saw to cut a circle in the old gas gauge - this holds the 200-400V voltmeter. I also used the hot knife to cut holes in the surround for the Hall-effect ammeter and the combo switch. Here it all is, test-fit in place:

Still to do on the dash:

Make room on the gauge backing for those deep gauges
Route 12V wiring from engine compartment to dash
Enlarge the holes behind the ammeter and the combo switch so the surround fits again
Finish disassembling the dash so I can get at the heater core
Reassemble everything
Profit!

Misc Parts

2008-10-19T20:13:00.000-07:00

This weekend, I finished up some of the miscellaneous things that needed doing. First, I removed the front rack and the driver's side support. I did this because I needed to build the mount for the power steering pump (as seen below). I also need the rack out of the way to remove the heater core, and it will make a lot of the 12V wiring simpler.

With the front rack out, I cut a notch in one of the vertical supports to ensure that the steering rod will always clear it:

I built the mounting for the power steering pump:

I inserted a 3/8-16 rivet nut as the lower attach point for the power steering pump mount:

And I welded the controller mount. I then painted the controller mount, the power steering pump mount, and the two DC-DC converter mounts:

Not shown, but I also took the opportunity to caulk around the under-seat battery boxes to prevent leaks.

Finding Places for Front Components

2008-10-05T22:46:00.000-07:00

To finish off Sunday night, I found homes for all the components. First, the vacuum pump and vacuum reservoir. I relocated some electronics that were near the battery (I think it is the starter relay - I'll double-check and, if so, it will be removed permanently):

Second, the power steering pump. This one is tricky. It is fairly heavy (12 pounds) and bulky. I found a place for it along the rack. It will need a rack of its own to hold it in place...

...so Sketchup to the rescue. After drawing a scale model of the power steering pump, I drew some rack pieces around the mounting holes:

Most pieces will be 1" by 1/8" bar stock. The piece on the left is 1/2" by 1/16" box tubing. The bolt on the lower right will go into the main mounting bar of the battery rack:

This is all a little tentative - I need to get some more accurate measurements. But it is a good starting point.

DC-DC Converter Mount

2008-10-05T22:42:00.001-07:00

The two threaded rods on the front of the front rack are an ideal place to hang the DC-DC converter. So, I doodled a converter up in Sketchup, and then designed two angle-brackets-with-box-tubes to slide down over the threaded rod and mount the converter:

I then built it. These are two 1.25x1.25 1/8" angle brackets, welded to a 0.5" 1/16" box tube, all 8 inches long:

After mounting and drilling the pieces, I decided 8" was too long, so I cut them back to 7" - this shows the shorter length. 8" would have interfered with the top of the front rack:

And here is the DC-DC converter in its final home. The only 1/4 20 bolts I could find were some grungy old carriage bolts - all the hardware stores are, of course, closed on Sunday night. I'll pick up some better bolts this week:

Note that both components which require cooling (the DMOC445 and the DC-DC converter) are directly behind the original front grill, for high airflow while moving.

Designing Controller Mount

2008-10-05T22:37:00.000-07:00

This evening was spent in the front compartment. First up: figuring out how to mount the DMOC445 controller securely. After snooping around, I found these weldnuts on either side of the frame rails in the engine compartment - they were not being used for anything:

So I cut a 3/16" 1.5 by 1.5 angle iron to length, notched one end, and drilled a hole in the other to fit between those two holes:

Here is the bolt going through the hole in the other side:

With this bracket in place, I test placed some smaller 1.25 by 1.25 1/8" bar stock on top of it (and on top of a 1.5" box tube in front to level things out):

After trimming the two smaller angle brackets, I inverted them (so the flat part faced up) and placed the DMOC445 on top. Fits nicely!

I still need to finish the part currently occupied by the 1.5" box tube - possibly just threaded rod with coupling nuts to act as spacers, but that will wait for another weekend. And these pieces need to be rattle-canned.

Painting racks...

2008-10-05T22:34:00.000-07:00

Saturday was Paint-the-Racks Day. It all starts with proper prep - a dose of Marine Clean, followed by a clean water wash and a soak in Metal Ready, and a final clean water wash and a heat-gun dry. And then, the paint. I painted the racks and boxes and stuck the boxes in while still wet (this way, scratches will "self-heal" a bit as the paint levels itself):

Here are the seat racks from below:

The upper rear rack got a pretty white coat to match the white Jeep:

And the top of the front rack now matches the bottom:

This is the last of the major painting - the rest can be done with rattle-cans.

Seat Boxes, III

2008-10-05T22:28:00.001-07:00

Friday, KatC and I worked on the seat boxes again. But first, early that morning, I said "bye-bye" to the old internal combustion engine. I tried to find a buyer, but nobody was terribly interested in a 22-year-old underperforming 4-cylinder engine. So, off to the salvage yard it went in my trusty pickup:

After work, attention turned to the seat boxes. Here are both racks and boxes, waiting to be installed:

But, before installation, we have one more hole to cut. Here is KatC making the first cuts with a cutoff wheel on the angle grinder (easier to make long straight cuts):

She finished off the corners with a Sawzall:

Proud of her destructive abilities...

Here's the second rack test-fit in its hole:

After dithering for a while, trying to figure out how to get bolts in the very tight spots around here, I gave up and went for welding. I seam-welded above the frame rail, and then spot welded both inside and outside around the rest of the edges:

And, with that, the construction of the battery racks is complete!

Polypropylene covers, I

2008-09-29T19:33:00.001-07:00

For electrical insulation and keeping water, dust out of the battery racks, each will have a polypropylene cover. I purchased some 1/4" thick polypro at a local plastic shop. I used this blade on my circular handsaw to cut it up (I found that Sharpies mark on it acceptably for guidelines):

Here is the front cover in place, with the hold-down bolted down over it:

Here is the view of it from below, with the hood closed. Very, very close to interfering - but it does not interfere:

This is a closeup of the threaded rod going into the top hold-down as well as the outlet hole for the 4/0 welding cable. The holes that the 3/8" rod go through are 7/16" in diameter to provide for just a little "slop" in getting the rack on (without that, you pretty much have to get all 6 holes lined up perfectly then drop the top on exactly vertically):

I also cut the cover for the lower rear rack. Here it is, with the hold-downs placed on top of it for effect:

I have a few more holes to drill in the upper rear rack and the under-seat racks, and then it's time for paint for them. Getting very very close to wiring time...

All Done With Welding?

2008-09-28T22:11:00.001-07:00

Today I did what I think is the final welding on battery racks / boxes / hold-downs. First, I finished the hold-down for the front rack. Here is what it looks like in Sketchup:

The protrusions are of two kinds. The first (6 of them) is a place for the threaded rod to attach to. The second (2 of them) is kind of a protective "cover" for holes in the rack to allow the 4/0 welding cable to enter/exit the rack. To make them, I started with 1.5" by 1.5" box tubing (3/16" walls):

I cut each piece in half, either straight or diagonally:

And then welded them in to place:

Here's the hold-down balanced on top of the threaded rod (on top because I have not yet drilled the holes for the rod to go through):

I also did the final welding on the upper rear rack. I created a cube missing two walls out of 1 1/4" by 1 1/4" (1/8" thick) angle stock:

I then welded that on to the upper rear battery rack. This also is a protective "cover" for a place where cable exits the box. It also, not coincidentally, reinforces the horizontal support so that a hole can be made in it.

I also welded on the threaded nuts for the hold-downs to screw into:

There are three remaining things to do on the racks:

Drill any required holes
Paint
Install

Front Hold-Down, I

2008-09-27T21:37:00.000-07:00

Today I worked on the hold-down for the front battery rack. First, I cut 1 1/2" by 3/16" angle stock to size and welded it together (it's basically identical to the dimensions of the base of the front rack):

Next, I test-fit it over some batteries in the front rack. I think I knew this was going to happen, but I had managed to forget about it - the hold-down interferes with a lip projecting from the firewall:

Here is the area of interference outlined with a Sharpie:

I'm not sure how structural this part is. But, just in case, rather than removing it, I just cut it a little and bent it up out of the way - the bent part should still provide some vertical stiffness:

As you can see, the hold-down no longer interferes with the firewall protrusion:

So, here is the hold-down in place. There is still a fair amount left to do - I need to put the crosspieces on, and I need to add the flanges where the bolts will clamp down on the 3/8" rod. Also, I need to cut two outlet holes in the front of this hold-down to allow the 4/0 welding cable to come in/out of the rack.

With the hold-down in place, I can now shorten the 3/8-16 rod. I left it 1/2" longer than the top of the hold-down (to account for 1/4" of polypropylene and 1/4" of threads for the nut to grip). And now, the true acid test - closing the hood. Unfortunately, it failed. So, I borrowed one of my daughters' lipsticks and marked the rod/nuts:

Here is where that touched the hood. I circled it on the left and right with a Sharpie to make it easier to see:

And here are the holes I drilled out so the hood can close:

With all that, here is the closed hood with the top in place:

Thinking back on it, I suspect what happened with my previous test was that I assumed that the outside corner was the most likely interference point. I did not think of the rod sticking up...

Upper Rear Rack,II

2008-09-27T07:57:00.000-07:00

This week I found a few spare moments to finish the upper rear rack by adding a cage around the top which will hold polypropylene sheets to enclose the batteries. Here is the design done in Google Sketchup (PDF version here):

I cut the pieces mostly out of 1" by 1/8" bar / angle stock - the cage is not really structural (other than under tension to hold the top on):

Here it is, all welded together:

And placed in its location:

Still a couple of things to do to this rack: it needs the nuts welded on for the top hold-downs; it needs a hole cut to allow the 4/0 welding cable to exit the box; and, of course, it needs to be painted.

Final Battery Layout!

2008-09-21T21:50:00.001-07:00

Well, with the racks all basically designed and nearly built, I believe I can declare victory over the battery layout. Here is a picture of it:

You can find the PDF file here. The orange interconnects will be copper strips. Each interconnect will consist of a stack of 3 1" by 1/16" strips. This gets a cross-sectional area of 0.1875" which compares well with the cross-sectional area of 4/0 welding cable (which is 0.166"). The strips will be cut longer than shown and then creatively bent to allow for flex. Each strip will be heat-shrink wrapped for insulation, and then the three will be stacked on top of each other and screwed in to the battery (with a generous dollop of Noalox all over the place).

Here is a picture for example of the battery interconnects that Electro Automotive did for the Volt914 / VoltsPorsche AC. The ElectroJeep interconnects will be different, since the batteries do not have "L" terminals but rather screw-in terminal posts:

As a reminder, here is the evolution of the ElectroJeep battery layout:

Version 1.0, January 2008:

Version 2.0, March 2008:

Version 3.0, July 2008:

There may be a few minor tweaks (the two diagonal interconnects in the lower rear battery rack, on the right side of the picture bother me - way too close even if insulated), but I expect this to be very close to the final layout.

Hey, Rocky, watch me pull an Electric Jeep out of my hat...

Lower Rear Rack, III

2008-09-21T19:44:00.001-07:00

As I mentioned in the previous post, I got tired of lugging the rear rack / box around (it's very heavy). So, today was the day to permanently install it. First, I cut a notch in it and top-coated it with UV-resistant POR-15 topcote:

The notch is designed to avoid this bump in the back of the Jeep. Without cutting the notch out, this bump puts pressure on the rear of the rack, causing a pronounced "bowing in" effect:

Before installation, I cleaned up the rear compartment and rattle-can painted it white (both for cosmetic reasons as well as to avoid rust):

I lowered the rack into place, using a floor jack to keep it from dropping all the way down yet:

I did this because I need to put sealer around it. I used GE Silicone II, as used in the Porsche:

I gooped a very wide bead all around the hole:

Then lowered the rack in place, installed the bolts, and put the batteries into their final locations:

Note that the sheet metal is now bent down over the back of the rack. The batteries and cover still fit under this sheet metal. I was careful to fill any gaps with the silicone.

Next: work beckons once again, but I may find a few spare moments to build the second seat rack or perhaps to finish the upper rear rack.

Seat Boxes, II

2008-09-21T19:34:00.001-07:00

Time to build the racks for the under-seat batteries. Getting accurate dimensions was tricky with the complicated curves under the seat. So, I cheated. I marked a hole the size of the battery box:

The front of the hole aligns exactly with the factory "drain plug" used during initial priming of the body - I knocked the plug out with a hammer (you can see the hole here). The outside cut of the hole is designed to be just about even with the "frame rail" beneath, to give the box extra security. I used a cutoff wheel on my grinder to cut the hole out (note the "flaps" - these stay attached and will be bolted to the rack):

And I test-fit the box in the hole. Just right. With the box in place (supported from below by a floor jack) I traced the contours of the hole on it.

With the box removed, I tweaked the contours to something reasonably easy to cut / bend / weld (you can see my first sketch of the upper part of the rack here):

With those measurements, I went inside and used Sketchup to design the complete rack. You can find a PDF blueprint here. This is a rendering with the box inside:

Here are the two side pieces cut, bent, and welded together, test-fit against the lines drawn on the box:

Here is the completed upper part of the rack, test-fit in the hole (this is a view toward the passenger's side from the driver's side):

Here is the completed rack with the box inside it. This is a very tight fit - the blueprints above were sized up a little to make it not quite so tight (so the second one I build should slide in more easily):

Here is the completed rack resting in its hole:

And here is a battery inside the box inside the rack:

Same thing, from below, to check for interference. This sags a little more than the actual mounting will, since it does not have bolts (or maybe rivets) attaching the rack to the sheet metal flaps:

Next task: installing the lower rear rack permanently (I'm tired of moving the rack around the garage...)

Seat Boxes, I

2008-09-19T18:53:00.000-07:00

Last post, if you recall, I designed the seat boxes - here is the pattern, for reference:

As with the sheet metal for the lower rear battery box, I printed it out on several sheets of 8.5x11 paper, taped it together and cut it out (the holes in the middle are extra taping points):

Since I was making two identical boxes, I just clamped two sheets together and taped the pattern on top of the stack:

Here is one of them, cut out and sanded down all pretty:

The folds are kind of tricky. If I had sheet metal wider than 24" I would not have done the pattern this way - but this is the only way it would fit on a 24x48 sheet of steel. First, I folded the upper lip over (to make a sturdy and non-sharp edge around the top). Next, I folded the "envelope flaps" partly over:

More folding. Here comes the tricky part - you need to fold it all up just about simultaneously or it does not mesh properly. Even as it meshes properly, there is some final hammering / pushing / bending needed to get it into box shape:

Here it is, completely folded and ready for welding:

To weld, I first used various clamps to keep the flaps down completely flat against the walls:

Here is KatC, spot-welding one of the boxes:

Given that this will have a complete rack supporting it, spot-welds are more than adequate. I will paint these and then put seam sealer around the edges to keep water out:

Next up - more welding on racks...

Tentative Seat Box Design

2008-09-13T15:46:00.000-07:00

Although I am 75 miles from the Jeep, I have my computer and Sketchup with me. So, here is a model of the under-seat box and rack. I'm sure of the box dimensions (the battery is the same as all the other batteries...) but I am not sure of the rack dimensions - I will need to measure very carefully.

So, here is a rendering of the box in the rack:

This is just the rack - conceptual at this point:

And this is the sheet metal pattern for the box:

Upper Rear Rack, I

2008-09-12T21:36:00.000-07:00

I found a few spare hours in the early morning / late evening this week to build the first part of the upper rear rack (it will hold 7 batteries). First, I planned it out in Sketchup:
Perspective view:

Exploded, so you can see how all the pieces are shaped and fit together. Would be nice if Sketchup had an "exploded view" option but I can't find it if it does. I prefer this kind of jigsaw-puzzle fitting together for some reason. I justify it by saying I can cut those straight lines more accurately than the diagonals the normal "picture frame" way would require. Also, I can grind the weld beads off closer than I could with the diagonals. But I suspect those are just rationalizations and I simply like the aesthetics of this kind of design:

So, off to the angle grinder and chopsaw I go. Again, I used a flapwheel sander to clean off the paint / grease / rust / etc. from the angle iron, and then chop-sawed them all to the proper lengths (which are written on them with a Sharpie so I can easily tell them apart):

Next, I marked the special cutouts with a Sharpie:

...and then used a cutting wheel on my angle grinder to cut them to shape:

Here is the outer part test-fit to make sure it looks right:

And here it is, all welded together and placed in the rear compartment for visualization and hole-drilling purposes (holes will be drilled through the upper rack and then through the lower rack at the front of the lower rack). My daughter KatC did one of the welds - her first one!

Here is the completed rack with batteries placed in it:

And here is a measurement of the clearance between a battery in the lower rear rack and the bottom of the upper rear rack - roughly 1/2 inch, which allows for 1/4 inch of polypropylene plus another 1/4 inch of spacers on between the batteries and the lid (to make it easier to route the interconnects):

With the upper rear rack assembled and in place, I can finally drill the holes through the lower rack and the body sheet metal. The holes fit 3/8 inch stainless steel bolts. As always, I drilled them progressively (starting with a 1/8 inch bit and moving up by 1/16 inch until I got to 3/8):

I then drilled the holes for the hold-down mounting bolts and welded the bolts in place on the lower rear rack (you can see one of the acorn nuts that will attach the hold-downs rolling around inside the lower rear rack):

With all that drilling and welding complete - it's time for paint! I used the POR-15 treatment again. Here is the outside after the first coat - I will also top-coat with a POR-15 UV-resistant black topcoat for enhanced durability:

And that's it for this week. This weekend, I am at Nan Desu Kan with my daughter again, so I won't make much progress. Short term list of things for next week:

Top coat the rear rack exterior
Paint and top coat the rear rack interior
Permanently attach the rear rack
Make a box for the upper rear rack (to prevent fingers / cargo / etc. from getting at high voltage)
Paint the upper rear rack and permanently attach it

If time allows, I will design and build the racks / boxes for the two batteries that go under the rear seat. We'll see...

Lower Rear Rack, II

2008-09-07T20:34:00.001-07:00

This weekend, I completed the sheet metal enclosure that I designed in the previous post. The reason for the enclosure is that this rack is both "outside" and "inside" the passenger compartment, and I don't want fumes, water, road debris, etc. getting inside.

The first step was to print up the plans at a 1:1 scale. Using an 8 1/2 x 11 printer means you have to tape lots of pieces of paper together:

Next, I took the paper patterns outside and test-fit them to the box. On the whole, it fit pretty well - but it shows that a little more height to the sides would not hurt (which I added as I cut the patterns out):

Before welding anything, I used this weld-thru primer on both faces of the metal that would touch (but not be 100% welded). This will prevent rust from starting - and, with the high heat of welding, rust starts almost immediately:

Here's the box with weld-thru primer on any surface that will be touching sheet metal:

I taped the templates to the sheet metal, then used a 4 1/2" cutoff wheel on my trusty angle grinder to cut out the pattern:

Both pieces of sheet metal have a "tab" that needs to get folded up to mach the angle stock on the bottom of the battery rack. So, I firmly clamped a spare piece of angle stock to the sheet metal and used my ball-peen hammer to "gently" form the tab to the 90 degree angle:

Here's the first piece, placed on the box with bending in progress. I used various clamps and weights to keep the metal in place while I used the ball-peen hammer to form the metal around the box:

I then spot-welded the enclosure on to the rack from the inside:

The second piece went smoothly too, very similar to the first piece (only a different pattern, obviously):

And here it is, all welded up. I estimate that I did almost 27 linear feet of welds to close all the seams (you can also see the spot welds that I did on the second piece near the front of the box):

And here is the completed box, with the exterior weld beads ground flat (to give less of a place for rust to start and to allow the box to drop in to the hole smoothly) and the flux residue sanded off:

The box still fits in its hole (although I did have to enlarge the corner near the top-right of the picture - that roughly 1/8" additional size was just enough to make it not fit):

Here is the completed box from below. You can see that it does not come close to interfering with anything. You can also see that the 3/16" angle stock on the top is actually resting on top of the unibody "frame rails" - this is a very good thing, since those are the primary structural members of the Jeep:

Jill asked, "what are those triangular areas in the corners for?" They are for two things - the high-voltage interconnect for the charger (at the most-positive point of the battery chain, on the right side of the box), and for one of the huge 400A fuses that protect the whole high-voltage system. Here is one of the fuses test-fit in the corner. A slightly tight fit, but should be OK. I will likely put some polypropylene in this area to insulate it from sparks / arcing:

Next up: painting this rack (after cleaning the flux crap out of the inside), and building the Upper Rear Rack.

Designing Rear Box Enclosure

2008-09-03T21:57:00.000-07:00

Tonight I also played with Sketchup and created a template for the sheet metal enclosure that will surround the lower rear rack. This will keep water and road debris out of that battery pack. Here is what it will look like installed:

And here is a template that I can replicate on two 24"x48" sheets of 20ga steel. Just need to cut, bend, and weld:

In addition to waterproofing, this should be a good additional support against fatigue cracks in the rack.

High Voltage Wiring Diagram

2008-09-03T21:10:00.000-07:00

It's getting dark earlier these days, so no time before / after work for actual metal fabrication. So, I spent some time creating the high-voltage wiring diagram. You can get the PDF here.

The parts list is as follows:

AC55 AC55 3-phase AC motor from Azure Dynamics
DMOC DMOC445 AC controller from Azure Dynamics
DC-DC DCDC 750 BC12 DC to DC (200-400V; for use with 12V aux battery) from Azure
Htr 2x 400V, 1000W ceramic heaters from Mor Electric
Ctctr Tyco Kilovac 500A 320V LEV200 Contactor (overkill...)
400A 2x Ferraz-Shawmut A50QS400-4 500VDC 400A fuses from evsource
30A Littelfuse KLKD030 600VDC 30A fuse from onlinecomponents
1.5A Littelfuse KLKD01.5 600VDC 1.5A fuse from onlinecomponents
50 mV Westach 237-150 150A 50mV shunt from westach.com
V Westach 2C5-84 200-400VDC voltmeter from westach.com
A Westach 2C6-14 -150-0-+150A DC ammeter from westach.com
Charger Manzanita Micro PFC-20 110-240V 20A battery charger
12V, 96V... Battery packs built from 12V Concorde Chairman AGM-1280T batteries

High-current wiring is 4/0 gauge welding cable
Medium-current wiring (charger, DC-DC converter) is 10 AWG primary wire
All other wiring is 16 AWG primary wire

High-current connectors are Cam-Lok400A 600VDC connectors from lightsonretail - NOT INTENDED FOR DISCONNECTING WITH LOAD APPLIED

Medium-current connectors are either Anderson SB-50 (charger) or Yazaki 2-pin (P/N 7222-4220-30) (DC-DC converter)

Lower Rear Rack, I

2008-09-01T22:04:00.000-07:00

With the 3-day Labor Day weekend, it was a good chance to tackle the biggest single fabrication job of the whole project - the lower rear rack. This is the rack which is sunk below the floor of the rear compartment. After some thought, I decided to go with 8 batteries in this rack instead of 9 - it yields a symmetrical design - which means that many parts are mirror images of another part, which makes it much easier to fabricate. Here are the plans, done in Google Sketchup:

Here is a Sketchup-generated picture of the designed rack:

One thing not shown in these plans and pictures is the sheet metal box that will be welded to this rack - I don't want water getting into the passenger compartment.

The first step was to start on the lower portion of the rack. I cut out the 8 pieces, sanded them, and test fit them:

They were then welded together (along with the diagonal supports at the corners). Next, I cut all the uprights - 6 angle brackets at the corners, and 5 pieces of 1 1/2" bar stock in between:

I welded the corner brackets on, then welded the top angle bracket cross-pieces on these. I did this so I could take actual measurements of the corner angle brackets and the rear bar:

After cutting the corner brackets, next step was to sand them all up nice and pretty (and cleaner for better welding). I used a cool flap-wheel sanding disk on my angle grinder - made short work of the rust, grease, and paint that was on the angle stock:

I then welded it all together...

...and ground off the tops of the weld beads where it mattered, and wire brushed the welding flux off of everything else:

Next challenge - the rear compartment. After removing all the carpet, it was clear that a minor rust problem was developing:

So, I used the flap-wheel disk and ground all the rusty spots down. One of the rusty spots actually penetrated - you can see the weld patch near the left rear whell-well and gas tank filler cover. Here it is, primed and ready for...

...cutting! I used a cutoff wheel on my angle grinder for most of the cuts, but some of the cuts were deeper (through non-necessary cross members). For those, it was Sawzall time:

Here is the completed hole. At the top, you can see the cross-members I needed to cut through. These were to support the gas tank, and are not needed for the electrical Jeep. They will provide extra sturdiness for the rear rack, though, so I won't remove them.

And here is the rear rack, dropped in to place! I had to enlarge the hole slightly (it's always easier to enlarge a hole than to make it smaller...) and had to bend up the sheet metal where the hatchback closing trim fits - it will get bent back once everything is mounted for good:

And here are 8 batteries test-fit in the box, all snug and happy:

Next steps for this rack: welding sheet metal around to make it waterproof; POR-15 and UV-resistant topcoat; seam-sealing; and final attachment. I also still need to fabricate the polypropylene top and steel hold-downs. Maybe next weekend... or I might work on the 7-battery upper rear rack next. Decisions, decisions.

Final Front Rack

2008-08-25T20:48:00.001-07:00

Life has conspired to make it hard to find time for working on the Jeep this week. But I did manage to finish up the front rack. I tapped the holes for various mounting points - note that the holes at the bottom of the uprights are *not* circular. They are ovals. This was a royal pain to do. The tool that finally worked was my Dremel with a tungsten carbide cutting bit. This worked well, but made thousands of tiny needle-like slivers which worked their way into my clothing (and any exposed skin). Be careful out there...

Here is the final rack, with 3/8 inch threaded rod connectors welded and rods inserted, and the rack bolted to the uprights. In the background is the ElectroJeep's German cousin, the volt914:

I then used POR-15 to paint the rack (including the degreaser / phosphoric acid rust converter steps) and mounted everything for real in the engine compartment:

Next weekend is Labor Day. Hopefully I'll manage to labor well and make lots of progress...

Front Rack Mounts

2008-08-15T21:14:00.001-07:00

This week, in the evenings, I've been working on the front rack mounting points. These have to be extremely sturdy - they will be supporting the weight of 440 pounds of batteries, and will have to handle acceleration and deceleration, too (not to mention the forces of a collision, Heaven forbid). I started with 1 1/2 inch box tubing, with 3/16 inch thick walls. I cut it to the desired lengths with a chop saw:

Here are the lengths of box tubing precariously balanced close to where they will end up. I did this to get a sense of where the top rails would be relative to the motor mounts:

A closeup of one of them shows the angle at which it crosses the mounting point - roughly 13 degrees:

And, of course, what would a good summer garage project be without hornets (scroll to the end of that post)? They seem attracted to the buzzing sound of power tools. I've spent almost as much time chasing these nasty little bugs as I've spent working.

Anyway, back to the real work. I removed the engine mounting brackets, which will get box tubing posts welded to them. After getting everything cleaned up, here is all of it (the driver's side bracket is on the left, the passenger's on the right):

There are little lips at the edge of the engine mount brackets. So I ground them off (my wife Jill got a nice spray of grinding sparks as she took this picture - oops - a definite case of "if you can read this you are too close!"):

I then welded the 8" box tube posts to the mounts. Despite the 90-degree weather, I'm wearing long pants, long sleeves, and heavy gloves, to avoid "weld-burn" which is pretty much exactly the same as sunburn:

And here are the brackets, with the posts attached:

They fit nicely in the engine compartment, very even and with ample clearance for the engine mounts:

I test-fit the rack to decide how far down the cross beams would go:

And here is what I decided - to knock off roughly 1/4 inch more in height so that the hood will definitely clear the batteries:

I welded the cross-members to the brackets:

I'm definitely getting better at welding. These are possibly the best welds I've done to date - these were just wire brushed to get the flux crap off - no grinding involved - these are the actual weld beads:

And here are the nearly complete brackets / mounts in place in the engine compartment:

...with the rack sitting on top:

With the mounts nearly complete, the assembly is sturdy enough to place an actual battery there for the first time. Looks good....

However, I've learned that looks can be deceiving. So, I performed a test. I took two pieces of foam-board (which together are slightly thicker than the plastic top plus hold-downs will be) and smeared sticky oil around on the top so I could see if it actually touched the hood when it is fully closed. As you can see, no oil ended up on the hood. This is the battery that is most likely to interfere with that diagonal structural member. But nothing touched, so everything looks good to go:

Next up - finishing the front rack by creating the lid. Originally, I was going to build a complete rack box up around it. But now, I think that is overkill. Instead, I'm going to weld 3/16" angle stock 1.5" wide together into a hold-down, and mount that over the plastic lid. And then screw the whole thing on with 8 3/8" threaded rods. Should be more than strong enough against lateral and vertical forces.

One more detail - I need to figure out some bracing for lateral and front/back motion. The mounts as designed are fine for the simple vertical forces, but the day-to-day acceleration / deceleration / turning forces will eventually weaken them unless braced.

Front Rack, Part II

2008-08-10T20:15:00.000-07:00

I got a little more time to work on the front rack, welding the cross-members in to the base. This picture shows 8 batteries nestled in the base, a perfect fit:

Here is the same rack, propped approximately in its final location. Next up - welding the supports from box tubing (1 1/2 inch size, with 3/16 inch walls). The rack will bolt on to the supports, and the supports will bolt in to the frame rail. I'm considering making the remainder of the rack a separate bolt-on piece so that it is not so heavy.

Here is what it is supposed to look like when all is said and done - from Google Sketchup:

Welding Racks, Part 1

2008-08-09T19:58:00.000-07:00

Today I completed one rack and got a good start on another. The completed rack is a single-battery rack to go in the engine compartment. Here it is after priming and painting:

And here it is with a battery snuggled down in it. The angles sticking out to either side will be drilled so that I can attach a hold-down (which will be attached to a plastic lid to keep fingers away from the 316-volt system):

I also got a start on the big 8-battery front rack. Note the scab plates in the middle of the left and right sides - I miscalculated by 1/2 an inch, which was more than enough to keep the batteries from fitting. After thinking about it for a bit, I just cut the left/right sides in half and butt-welded an angle bracket scab plate across. Should be plenty strong, especially given that the battery rack mounting points (4 of them) will be at about the CG of the cut sections.

This is the same picture, zoomed in so you can see where I plan on attaching the mounts, circled in red. I plan on using 1 1/2" box tubing (with 3/16" walls) for the vertical legs. Either 1 1/2 angle stock or box tubing will serve as the supporting crossmember.

Charger is here!

2008-08-09T19:53:00.001-07:00

The charger arrived today. It took a while, but Ryan at EV Source was very helpful and honest about the delivery issues. It is a Manzanita Micro PFC-20. There are two neat features that this has over the Zivan NG-3. First, it can adapt to AC line voltages from 120 to 240 volts. Second, it has a built-in data bus interface which you can use for better equalization of batteries (especially important with AGM batteries).

This is the last major component to arrive. On to building battery racks and getting ready to string it all together...

Playing with Sketchup

2008-07-27T23:15:00.001-07:00

I spent the evening playing with Google Sketchup, a free 3D "CAD-lite" program. It has a $450 professional edition as well, but I did not get that - just the free version. To learn it, I designed my rear battery rack. The whole thing will be made out of 1 1/2" angle iron, 3/16" thick. Here is the top view, with the top dimensions:

Here is the bottom view:

Here is from the right side:

Here is an iso view:

Here is a perspective iso render, with texture and shadows:

And here is a render with the 9 batteries installed:

Sketchup seems more than adequate for simple drawings like this. I would not design anything more major than these components with it, though.

One other detail - although this set of drawings shows just the rack, the entire box will be enclosed (since it fills a hole to be cut into the cargo area). I plan on using relatively thin steel and welding it to the outside of the rack. Proably 20 gauge or so.

Motor Installed!

2008-07-26T20:54:00.000-07:00

After a week of vacation, time to get back at it. Today, the task was to install the motor for real. The first step is to install the flywheel. The instructions call for 1.415" +/- 0.01" - with the modified hub / bushing, it was very straightforward to get the flywheel there:

A trick I figured out to make installing things easier was to push the bushing in as far as possible (with the flywheel installed and without using excessive force), and measure that distance. In this case, it was 1.275". This means that the hub has to come out 0.140" from its maximum "in" distance. That distance was 0.750", which means that the hub has to be 0.890" +/-1 0.01" - here is that distance shown:

It is *much* easier to measure this distance as you tighten the taperlock hub than it is to do as suggested in the "VoltsPorsche 914" manual - in that case, it suggests you tighten it *almost* all the way (so it is difficult to slide back and forth) and then adjust, remove the flywheel, and tighten for real. With the volt914, I kept moving the hub when I removed or reattached the flywheel. I like this "measure the bushing distance" method much more - I only had to remove / reattach the flywheel *once*.

With the flywheel mounted (and the bolts torqued to 50 foot pounds plus 60 degrees), time for the pilot bushing. A piece of cake, using a socket as a drift:

Here it is, installed:

Next, the clutch. You insert a pilot tool to keep the clutch properly centered when you install the pressure plate (side note - this is the last picture ever to be taken with my trusty garage digicam - it got dropped in an oil bucked right after this picture was taken):

Here is the pressure plate installed (the bolts are torqued to 23 foot pounds as per manufacturer's specs). You can also see one of the two brass bushings I bought to replace the transmission locator pins, which I cannot seem to remove from the original gas engine no matter how I try:

As part of the clutch kit, I also got a new throwout bearing. Here it is, on the throwout lever plate:

And here is the plate / bearing installed in the transmission, with the driveshaft greased up and ready to mate with the motor:

While the motor was out for this procedure, I took the opportunity to fix the interference problem with the motor mount:

Finally, with everything in place, I removed the lifting eye. This was trickier than expected. Basically, you are supposed to "tap it with a hammer" and it will slide out - this concept is well illustrated by the picture here:

However, there were complications. Either when it was installed, or during all the hoisting I've done over the past few months, a large burr developed on the heatsink fins. So, I had to take my angle grinder to them and widen the groove somewhat. And then I had to use my Big Friendly Hammer (a 6 pound sledge) with full-force "taps". The lifting eye was pretty banged up by all this, but I got it off:

Just for grins, with the lifting eye removed, I dropped my 3x1 battery box on top for a test fit:

Whew! Now, to weld the battery racks and boxes...

Final Battery Layout?

2008-07-12T22:04:00.000-07:00

With the motor in its final location, it's time to look at battery placement for real. After cutting the carpet from the cargo area, it became obvious where the limits would be (you can see the spot welds of the frame rails to the floor pan). It also became obvious that my original 3x3 layout will not fit in the area allocated, so it's time for an asymmetrical layout that matches the available space. In addition, looking more closely under the rear seat, it is clear that only two batteries will fit here. Four batteries are not possible without cutting the frame rail, which is an incredibly bad idea.

So, here is a test fit with actual batteries in the rear. The five batteries near the seat back are in their final position - a box will be built to contain them. The three batteries behind those five will join six others sunk into the floor of the cargo area. A box will be built to contain them as well:

In the front, the motor mounting provides a challenge for laying the batteries out as I had originally planned. Instead, I'll go with three groups of three, with the last battery replacing the large starter battery (a smaller aux battery will go on the driver's side, along with the DC-DC converter). Here is a test fit of the three groups of three - the box in the lower right corner is the same volume as three of my batteries.

Due to space constraints, there will not be a box completely enclosing the front batteries. Instead, there will just be racks supporting it, along with a plastic top / hold-down for each group of three (and the solo battery) to prevent the batteries from flying around and to prevent fingers from accidentally brushing up against 312-volt power.

The good news is, even with two-by-fours and 3/4 inch plywood in the way, the trunk still closes with the batteries in the above position, so I think that this design will work:

So, here is the new component layout. The controller still goes in the front, above a group of three batteries. Two more groups of three are in the front, along with a solo replacing the large starting battery. Two batteries are under the rear seat, and fourteen are in the rear cargo area (9 of which will be sunk below the floor level):

Business travel and vacation will interrupt progress for a couple of weeks; when I return, it will be time to start fabricating racks and boxes!

Motor Mount Fabrication

2008-07-12T20:50:00.000-07:00

This week I fabricated the motor mount. I stuck fairly close to my original design, but tweaked it as I went along. It all started with 1 1/2 inch steel straps and angle stock - here is the first set, clamped and waiting to be welded (you can see where I wire-wheeled off the primer to make a clean weld):

This was my first attempt at flux-core welding (my previous welding experience was mig welding) so it is a little rough, but the penetration is good, and it is plenty strong:

I cut one side of the angle stock for the bend in the hanger - this leaves an unbroken strap all the way around. Here is the hanger cut, bent, and clamped in preparation for welding:

And here it is, all assembled. I decided not to add the forks from the original design - it would have made it so it did not rotate, and I think a slight rotation will be necessary.

After drilling the holes for attaching the motor, the next step is priming (here you can see the notch I had to cut in the hanger due to interference from the original Jeep motor mount):

Finally, it gets a coat of enamel. With all that done, here it is installed (on the left you can see how the notch fits against the mount):

And here is the motor, resting all happy in its new home:

That lifting eye has been handy so far, but the time is coming when it is just going to be in the way. Azure Dynamics' website says it is removable, but darned if I can figure out how. I'll send them email and see what they say.

Finally, after test placing 480 pounds of batteries in the front, I went under the Jeep to check lower interference. Unfortunately, there is some, with the front axle "pumpkin" (higlighted in red here):

When I remove the motor to do the final flywheel/clutch assembly, I'll take out the mount and grind a new radius on that corner, as outlined in green, to remove the interference.

Electro Automotive Delivers

2008-07-12T20:10:00.000-07:00

Back in May, Electro Automotive shipped me the profile plate, motor ring, splined bushing, and taperlock hub. Unfortunately, the splined bushing was too long and prevented the flywheel from being properly placed. In this photo, you can see how far out the hub stuck with the too-long bushing:

EA said, "send it back and we'll fix it" so I did, but before I sent it back, I took some measurements. The bushing was 1.75" long, as shown here:

When inserted into the hub, the bushing stuck out about 1/8 inch:

I sent them the hub and bushing a few weeks ago, and it showed up this week, all better! Here you can see that the new bushing is 1.375" long (a full 3/8 inch shorter):

When inserted into the hub, it now is about 1/8 inch below the top of the hub:

Here is a test fit of the bushing and hub - you can see that the hub is much farther back inside the profile plate. This should be plenty of room to adjust the flywheel distance.

I have to say, I have been very happy with Electro Automotive's responsiveness here. They have changed their operations to try to do a better job at order fulfillment, and it shows. Thanks, EA!

Cam-Lok High Voltage Connectors

2008-07-11T22:56:00.000-07:00

In this posting, intergalactic mentioned the following valuable advice:

Don't use Anderson connectors. The SB50 and SB350 styles don't seal and if wet will short out and burn up. The connectors used for long welding cables or outdoor power supplies with the tapered rubber boots work well. Cam-Lok, I think.

After some googling, I found an online retailer (http://www.lightsonretail.com) who carried Cam-Lock style connectors which would work with 4/0 welding cable. These are rated for 400A at 600VDC, so should work well for the 312V Jeep. They are waterproof, interlocking, and very large.

On the left are the components for the female connector; on the right, the male:

This picture shows how the components interconnect:

And this picture shows the female connector with the cam component inserted:

I got enough of the connectors to isolate each major battery group so that I can work on lower voltages than 312V. I found 144V to be dangerous enough; I don't want to work directly on higher voltages if it can be avoided. Which it can by making each battery pack independently connect into the series with these Cam-Lok connectors.